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Overclocking E6600 on Asus P5W DH Deluxe

Discussion in 'Overclocking' started by Nick Le Lievre, Apr 1, 2007.

  1. Can somebody explain the fsb/multiplier settings the chip would be set to at
    stock... and what changes I would need to make to run this at 2.8 > 3.0ghz

    I havent built a system with core 2 duo yet and my expierience with
    overclocking is with thoroughbred B AMD XP chips which overclocked by
    running them at 166mhz fsb rather then 133 what do you do with core 2 duo
    chips to overclock.

    Thanks.
     
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  2. Phil Weldon

    Phil Weldon Guest

    'Nick Le Lievre' wrote:
    | Can somebody explain the fsb/multiplier settings the chip would be set to
    at
    | stock... and what changes I would need to make to run this at 2.8 > 3.0ghz
    |
    | I havent built a system with core 2 duo yet and my expierience with
    | overclocking is with thoroughbred B AMD XP chips which overclocked by
    | running them at 166mhz fsb rather then 133 what do you do with core 2 duo
    | chips to overclock.
    _____

    You overclock the Intel E6600 the same as with all Intel CPUs produced this
    century save for the Core 2 Extreme X6800 and the Core 2 Extreme QX6700.
    You raise the FrontSide Bus speed because the multiplier is locked and
    cannot be increased. The 65 nm feature size Core 2 Duo Intel series is so
    overclockable that you have a good chance of overclocking from the stock 2.4
    GHz to 3.0 GHz with the standard Intel boxed retail heatsink/fan and the
    default core voltage. Since that means an FSB of 1333 MHz, you need a
    motherboard that will work with the FSB set to 1333, and will, since there
    is no PC10600 yet, need to set the CPU:Memory clock ratio to run the memory
    you actually have within its speed capabilities. Things like raising the
    CPU core voltage and extra cooling for even higher overclocks are used much
    the same as for AMD CPUs. (If you wish, you can think of an FSB of 1333 MHz
    as 4 X 333 MHz.)

    Phil Weldon

    "Nick Le Lievre" <> wrote in message
    news:460fb2e1$0$21941$...
    | Can somebody explain the fsb/multiplier settings the chip would be set to
    at
    | stock... and what changes I would need to make to run this at 2.8 > 3.0ghz
    |
    | I havent built a system with core 2 duo yet and my expierience with
    | overclocking is with thoroughbred B AMD XP chips which overclocked by
    | running them at 166mhz fsb rather then 133 what do you do with core 2 duo
    | chips to overclock.
    |
    | Thanks.
    |
    |
     
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  3. "Phil Weldon" <> wrote in message
    news:ePOPh.133340$...
    > 'Nick Le Lievre' wrote:
    > | Can somebody explain the fsb/multiplier settings the chip would be set
    > to
    > at
    > | stock... and what changes I would need to make to run this at 2.8 >
    > 3.0ghz
    > |
    > | I havent built a system with core 2 duo yet and my expierience with
    > | overclocking is with thoroughbred B AMD XP chips which overclocked by
    > | running them at 166mhz fsb rather then 133 what do you do with core 2
    > duo
    > | chips to overclock.
    > _____
    >
    > You overclock the Intel E6600 the same as with all Intel CPUs produced
    > this
    > century save for the Core 2 Extreme X6800 and the Core 2 Extreme QX6700.
    > You raise the FrontSide Bus speed because the multiplier is locked and
    > cannot be increased. The 65 nm feature size Core 2 Duo Intel series is so
    > overclockable that you have a good chance of overclocking from the stock
    > 2.4
    > GHz to 3.0 GHz with the standard Intel boxed retail heatsink/fan and the
    > default core voltage. Since that means an FSB of 1333 MHz, you need a
    > motherboard that will work with the FSB set to 1333, and will, since there
    > is no PC10600 yet, need to set the CPU:Memory clock ratio to run the
    > memory
    > you actually have within its speed capabilities. Things like raising the
    > CPU core voltage and extra cooling for even higher overclocks are used
    > much
    > the same as for AMD CPUs. (If you wish, you can think of an FSB of 1333
    > MHz
    > as 4 X 333 MHz.)
    >


    So what is an FSB of 1333mhz is that DDR2 1333mhz... i mean in terms of like
    200mhz fsb used to be 400mhz DDR. What would 1333mhz DDR2 be in terms of fsb
    speed.... don't these core 2 duo chips sometimes use and fsb of 166mhz still
    becuase on my brothers PC I he was running an E6300 at 333mhz DDR I think...
    that was really 166mhz fsb or was it actually 333fsb and things have moved
    on a lot since the AMD days. What are the current fsb speeds used on Core 2
    Duo CPUs and can you tell me the DDR speed and the actual non DDR speed as
    what you'd actually set in the BIOS... the DDR FSB is only theoretical
    becuase the ram runs at double data rate.... has this increased further
    since DDR2 is it now quadruple data rate? I am confused.
     
  4. Phil Weldon

    Phil Weldon Guest

    'Nick Le Lievre' wrote, in part:
    | So what is an FSB of 1333mhz is that DDR2 1333mhz... i mean in terms of
    like
    | 200mhz fsb used to be 400mhz DDR. What would 1333mhz DDR2 be in terms of
    fsb
    _____

    DDR2 has nothing to do with the FrontSide Bus speed.

    The Intel Pentium and Core 2 Duo CPUs use a 'quad-pumped' memory transfer; 4
    memory transfer phases per memory transfer clock with SDRAM, RDRAM, DDR RAM,
    and DDR2 RAM.

    The Intel Core 2 Duo CPU has an X9 multiplier.

    This multiplier cannot be increased.

    The number you set in the BIOS to get a 3 GHz CPU clock for the E6600 is 333
    MHz.

    That is the only choice to get 3.0 GHz from a 2.4 GHz Intel CPU.

    The E6600 has a multiplier of 9.

    266 MHz * 9 = 2.4 GHz (that's the standard speed for an E6600)

    333 MHz * 9 = 3 GHz (that's an easy overclock for an E6600)

    400 MHz * 9 = 3.6 GHz ( about the limit for an E6600 without exotic cooling)

    If the motherboard uses DDR2 memory, to get a CPU clock rate for your E6600
    you either must have DDR2 memory that will work at PC10600 rates, OR you
    must use a CPU:memory ratio that brings the memory clock down to whatever
    speed you CAN get out of your memory.

    Phil Weldon

    "Nick Le Lievre" <> wrote in message
    news:460fbba1$0$21942$...
    | "Phil Weldon" <> wrote in message
    | news:ePOPh.133340$...
    | > 'Nick Le Lievre' wrote:
    | > | Can somebody explain the fsb/multiplier settings the chip would be set
    | > to
    | > at
    | > | stock... and what changes I would need to make to run this at 2.8 >
    | > 3.0ghz
    | > |
    | > | I havent built a system with core 2 duo yet and my expierience with
    | > | overclocking is with thoroughbred B AMD XP chips which overclocked by
    | > | running them at 166mhz fsb rather then 133 what do you do with core 2
    | > duo
    | > | chips to overclock.
    | > _____
    | >
    | > You overclock the Intel E6600 the same as with all Intel CPUs produced
    | > this
    | > century save for the Core 2 Extreme X6800 and the Core 2 Extreme QX6700.
    | > You raise the FrontSide Bus speed because the multiplier is locked and
    | > cannot be increased. The 65 nm feature size Core 2 Duo Intel series is
    so
    | > overclockable that you have a good chance of overclocking from the stock
    | > 2.4
    | > GHz to 3.0 GHz with the standard Intel boxed retail heatsink/fan and the
    | > default core voltage. Since that means an FSB of 1333 MHz, you need a
    | > motherboard that will work with the FSB set to 1333, and will, since
    there
    | > is no PC10600 yet, need to set the CPU:Memory clock ratio to run the
    | > memory
    | > you actually have within its speed capabilities. Things like raising
    the
    | > CPU core voltage and extra cooling for even higher overclocks are used
    | > much
    | > the same as for AMD CPUs. (If you wish, you can think of an FSB of 1333
    | > MHz
    | > as 4 X 333 MHz.)
    | >
    |
    | So what is an FSB of 1333mhz is that DDR2 1333mhz... i mean in terms of
    like
    | 200mhz fsb used to be 400mhz DDR. What would 1333mhz DDR2 be in terms of
    fsb
    | speed.... don't these core 2 duo chips sometimes use and fsb of 166mhz
    still
    | becuase on my brothers PC I he was running an E6300 at 333mhz DDR I
    think...
    | that was really 166mhz fsb or was it actually 333fsb and things have moved
    | on a lot since the AMD days. What are the current fsb speeds used on Core
    2
    | Duo CPUs and can you tell me the DDR speed and the actual non DDR speed as
    | what you'd actually set in the BIOS... the DDR FSB is only theoretical
    | becuase the ram runs at double data rate.... has this increased further
    | since DDR2 is it now quadruple data rate? I am confused.
    |
    |
     
  5. "Phil Weldon" <> wrote in message
    news:7NQPh.17140$...
    >
    > If the motherboard uses DDR2 memory, to get a CPU clock rate for your
    > E6600
    > you either must have DDR2 memory that will work at PC10600 rates, OR you
    > must use a CPU:memory ratio that brings the memory clock down to whatever
    > speed you CAN get out of your memory.
    >


    So if I want to get 333 * 9 out of my mates E6600 I would need PC10600 DDR2
    memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I use?
     
  6. Phil Weldon

    Phil Weldon Guest

    'Nick Le Lievre' wrote:
    | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    DDR2
    | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I use?
    _____

    5 : 3

    Your friend's PC6400 DDR2 memory is specified to operate with a 200 MHz
    clock.
    He has an E6600 CPU that is specified to operate with a 266 MHz clock.

    E6600 CPU at 2.4 GHz and PC6400 memory at specification speed requires a CPU
    : memory clock ratio of 266 MHz / 200 MHz = 4 : 3

    E6600 CPU at 3.2 GHz and PC6400 memory at specification speed requires a CPU
    : memory clock ratio of 333 MHz / 200 MHz = 5 : 3

    (Since there is no CPU : memory clock ratio between 4 : 3 and 5 : 3 you must
    use the 5 : 3 ratio for overclocking to 3.0 GHz)

    Memory can also be overclocked. You may find that the PC6400 memory will
    operate at with a clock speed of more than 200 MHz, and that you can
    overclock the E6600 to more than 3.2 GHz with a CPU : memory clock ratio of
    5 : 3 and a FSB clock of more than 333 MHz.

    Phil Weldon

    "Nick Le Lievre" <> wrote in message
    news:4612673b$0$21944$...
    | "Phil Weldon" <> wrote in message
    | news:7NQPh.17140$...
    | >
    | > If the motherboard uses DDR2 memory, to get a CPU clock rate for your
    | > E6600
    | > you either must have DDR2 memory that will work at PC10600 rates, OR you
    | > must use a CPU:memory ratio that brings the memory clock down to
    whatever
    | > speed you CAN get out of your memory.
    | >
    |
    | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    DDR2
    | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I use?
    |
    |
     
  7. Guest

    On Apr 3, 7:10 pm, "Phil Weldon" <> wrote:
    > 'Nick Le Lievre' wrote:
    >
    > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    > DDR2
    > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I use?
    > _____
    >
    > 5 : 3
    >
    > Your friend's PC6400 DDR2 memory is specified to operate with a 200 MHz
    > clock.
    > He has an E6600 CPU that is specified to operate with a 266 MHz clock.
    >
    > E6600 CPU at 2.4 GHz and PC6400 memory at specification speed requires a CPU
    > : memory clock ratio of 266 MHz / 200 MHz = 4 : 3
    >
    > E6600 CPU at 3.2 GHz and PC6400 memory at specification speed requires a CPU
    > : memory clock ratio of 333 MHz / 200 MHz = 5 : 3
    >
    > (Since there is no CPU : memory clock ratio between 4 : 3 and 5 : 3 you must
    > use the 5 : 3 ratio for overclocking to 3.0 GHz)
    >
    > Memory can also be overclocked. You may find that the PC6400 memory will
    > operate at with a clock speed of more than 200 MHz, and that you can
    > overclock the E6600 to more than 3.2 GHz with a CPU : memory clock ratio of
    > 5 : 3 and a FSB clock of more than 333 MHz.
    >
    > Phil Weldon
    >
    > "Nick Le Lievre" <> wrote in messagenews:4612673b$0$21944$...
    > | "Phil Weldon" <> wrote in message
    > |news:7NQPh.17140$...
    > | >
    > | > If the motherboard uses DDR2 memory, to get a CPU clock rate for your
    > | > E6600
    > | > you either must have DDR2 memory that will work at PC10600 rates, OR you
    > | > must use a CPU:memory ratio that brings the memory clock down to
    > whatever
    > | > speed you CAN get out of your memory.
    > | >
    > |
    > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    > DDR2
    > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I use?
    > |
    > |


    Phil, sorry to intervene but you seem to forget that for DDR2 memory
    the bus clock is twice the mem clock. As a consequence, the clock you
    must use to get PC6400 (DDR2 800) mem to stock speed is 400 MHz, not
    200.
    So, to have a 1:1 ratio with the E6600 at 3Ghz (333 MHz * 9) , you
    only have to use DDR2 667 chips (PC5300 modules). No need to search
    for PC10600 modules.
    This is exactly what I am using in my PC now.
     
  8. Phil Weldon

    Phil Weldon Guest

    'mcarleer' wrote:
    | Phil, sorry to intervene but you seem to forget that for DDR2 memory
    | the bus clock is twice the mem clock. As a consequence, the clock you
    | must use to get PC6400 (DDR2 800) mem to stock speed is 400 MHz, not
    | 200.
    | So, to have a 1:1 ratio with the E6600 at 3Ghz (333 MHz * 9) , you
    | only have to use DDR2 667 chips (PC5300 modules). No need to search
    | for PC10600 modules.
    | This is exactly what I am using in my PC now.
    _____

    Please DO intervene. It is this sort of 'peer review' that makes
    alt.comp.hardware.overclocking useful.

    Well, the conventional number usage is not very clear, but my understanding
    is that PC1066 / PC8500 memory is needed to use the same clock for memory
    and the CPU (a 1 : 1 ratio) with an E6600 at stock speed.

    The stock clock for the E6600 is 266 MHz, then the FSB is 4 X 266 MHz = 1066
    MHz. The E6600 CPU stock speed is 2.4 GHz (9 X 266 MHz = ~ 2.4 GHz.) If
    the memory cannot operate at a 266 MHz clock then the ratio must be changed
    to from 1 : 1. DDR2 PC6400 memory is also called PC800 (6400/8 = 800)
    memory; it is specified for a 200 MHz clock. DDR2 PC8500 memory is also
    called PC1066 (8500/8 = ~ 1066) memory; it is specified for a 266 MHz clock,
    the same as the stock clock speed for the E6600. For the original poster to
    use a 333 MHz clock speed for the CPU ( giving an overclock to 3.0 GHz) and
    for the memory, the memory would have to operate at the PC1333 (PC10600)
    level.

    PC6400 (PC800) is certified for a clock of 200 MHz to operate that
    memory,within specifications, with a CPU clock of 333 MHz would require the
    CPU clock : memory clock ratio to be 5:3.

    So, no matter the confused nomenclature, the fact is that PC 6400 (PC800)
    memory cannot operate within specs with a 333 MHz clock speed. Were the
    facts as you present them, there would hardly be a market for PC8500
    (PC1066) and PC10600 (PC1333) memory. I don't know what system you
    have )but if (assuming it uses an Intel CPU) the FrontSide Bus is 1066 MHz,
    then your CPU clock : memory clock ratio is NOT 1:1 unless you are
    overclocking that PC800 memory to PC1066 levels. For the original poster it
    is possible that he could overclock PC1066 (PC8500) memory to PC1333
    (PC10600) levels and use 333 MHz for the CPU and memory clocks. With PC6400
    (PC800) memory that is HIGHLY unlikely.

    Phil Weldon

    P.S. If you have used your real email identity for this post, be prepared
    for spam and possible maliciously infected email. Spammers regularly
    harvest email addresses from Usenet posts. Some Internet worms ('Swen' in
    particular) harvest email addresses from Usenet posts and use those
    addresses as 'To:' AND as bogus 'From:' fields. That is why I use
    ''. Other posters just obfuscate the email
    identity by replacing the '@' with 'at'.





    <> wrote in message
    news:...
    | On Apr 3, 7:10 pm, "Phil Weldon" <> wrote:
    | > 'Nick Le Lievre' wrote:
    | >
    | > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    | > DDR2
    | > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I
    use?
    | > _____
    | >
    | > 5 : 3
    | >
    | > Your friend's PC6400 DDR2 memory is specified to operate with a 200 MHz
    | > clock.
    | > He has an E6600 CPU that is specified to operate with a 266 MHz clock.
    | >
    | > E6600 CPU at 2.4 GHz and PC6400 memory at specification speed requires a
    CPU
    | > : memory clock ratio of 266 MHz / 200 MHz = 4 : 3
    | >
    | > E6600 CPU at 3.2 GHz and PC6400 memory at specification speed requires a
    CPU
    | > : memory clock ratio of 333 MHz / 200 MHz = 5 : 3
    | >
    | > (Since there is no CPU : memory clock ratio between 4 : 3 and 5 : 3 you
    must
    | > use the 5 : 3 ratio for overclocking to 3.0 GHz)
    | >
    | > Memory can also be overclocked. You may find that the PC6400 memory
    will
    | > operate at with a clock speed of more than 200 MHz, and that you can
    | > overclock the E6600 to more than 3.2 GHz with a CPU : memory clock ratio
    of
    | > 5 : 3 and a FSB clock of more than 333 MHz.
    | >
    | > Phil Weldon
    | >
    | > "Nick Le Lievre" <> wrote in
    messagenews:4612673b$0$21944$...
    | > | "Phil Weldon" <> wrote in message
    | > |news:7NQPh.17140$...
    | > | >
    | > | > If the motherboard uses DDR2 memory, to get a CPU clock rate for
    your
    | > | > E6600
    | > | > you either must have DDR2 memory that will work at PC10600 rates, OR
    you
    | > | > must use a CPU:memory ratio that brings the memory clock down to
    | > whatever
    | > | > speed you CAN get out of your memory.
    | > | >
    | > |
    | > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    | > DDR2
    | > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I
    use?
    | > |
    | > |
    |
    | Phil, sorry to intervene but you seem to forget that for DDR2 memory
    | the bus clock is twice the mem clock. As a consequence, the clock you
    | must use to get PC6400 (DDR2 800) mem to stock speed is 400 MHz, not
    | 200.
    | So, to have a 1:1 ratio with the E6600 at 3Ghz (333 MHz * 9) , you
    | only have to use DDR2 667 chips (PC5300 modules). No need to search
    | for PC10600 modules.
    | This is exactly what I am using in my PC now.
    |
     
  9. Guest

    On Apr 19, 9:40 pm, "Phil Weldon" <> wrote:
    > 'mcarleer' wrote:
    >
    > | Phil, sorry to intervene but you seem to forget that for DDR2 memory
    > | the bus clock is twice the mem clock. As a consequence, the clock you
    > | must use to get PC6400 (DDR2 800) mem to stock speed is 400 MHz, not
    > | 200.
    > | So, to have a 1:1 ratio with the E6600 at 3Ghz (333 MHz * 9) , you
    > | only have to use DDR2 667 chips (PC5300 modules). No need to search
    > | for PC10600 modules.
    > | This is exactly what I am using in my PC now.
    > _____
    >
    > Please DO intervene. It is this sort of 'peer review' that makes
    > alt.comp.hardware.overclocking useful.
    >
    > Well, the conventional number usage is not very clear, but my understanding
    > is that PC1066 / PC8500 memory is needed to use the same clock for memory
    > and the CPU (a 1 : 1 ratio) with an E6600 at stock speed.
    >
    > The stock clock for the E6600 is 266 MHz, then the FSB is 4 X 266 MHz = 1066
    > MHz. The E6600 CPU stock speed is 2.4 GHz (9 X 266 MHz = ~ 2.4 GHz.) If
    > the memory cannot operate at a 266 MHz clock then the ratio must be changed
    > to from 1 : 1. DDR2 PC6400 memory is also called PC800 (6400/8 = 800)
    > memory; it is specified for a 200 MHz clock. DDR2 PC8500 memory is also
    > called PC1066 (8500/8 = ~ 1066) memory; it is specified for a 266 MHz clock,
    > the same as the stock clock speed for the E6600. For the original poster to
    > use a 333 MHz clock speed for the CPU ( giving an overclock to 3.0 GHz) and
    > for the memory, the memory would have to operate at the PC1333 (PC10600)
    > level.
    >
    > PC6400 (PC800) is certified for a clock of 200 MHz to operate that
    > memory,within specifications, with a CPU clock of 333 MHz would require the
    > CPU clock : memory clock ratio to be 5:3.
    >
    > So, no matter the confused nomenclature, the fact is that PC 6400 (PC800)
    > memory cannot operate within specs with a 333 MHz clock speed. Were the
    > facts as you present them, there would hardly be a market for PC8500
    > (PC1066) and PC10600 (PC1333) memory. I don't know what system you
    > have )but if (assuming it uses an Intel CPU) the FrontSide Bus is 1066 MHz,
    > then your CPU clock : memory clock ratio is NOT 1:1 unless you are
    > overclocking that PC800 memory to PC1066 levels. For the original poster it
    > is possible that he could overclock PC1066 (PC8500) memory to PC1333
    > (PC10600) levels and use 333 MHz for the CPU and memory clocks. With PC6400
    > (PC800) memory that is HIGHLY unlikely.
    >
    > Phil Weldon
    >
    > P.S. If you have used your real email identity for this post, be prepared
    > for spam and possible maliciously infected email. Spammers regularly
    > harvest email addresses from Usenet posts. Some Internet worms ('Swen' in
    > particular) harvest email addresses from Usenet posts and use those
    > addresses as 'To:' AND as bogus 'From:' fields. That is why I use
    > ''. Other posters just obfuscate the email
    > identity by replacing the '@' with 'at'.
    >
    > <> wrote in message
    >
    > news:...
    > | On Apr 3, 7:10 pm, "Phil Weldon" <> wrote:
    > | > 'Nick Le Lievre' wrote:
    > | >
    > | > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    > | > DDR2
    > | > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I
    > use?
    > | > _____
    > | >
    > | > 5 : 3
    > | >
    > | > Your friend's PC6400 DDR2 memory is specified to operate with a 200 MHz
    > | > clock.
    > | > He has an E6600 CPU that is specified to operate with a 266 MHz clock.
    > | >
    > | > E6600 CPU at 2.4 GHz and PC6400 memory at specification speed requires a
    > CPU
    > | > : memory clock ratio of 266 MHz / 200 MHz = 4 : 3
    > | >
    > | > E6600 CPU at 3.2 GHz and PC6400 memory at specification speed requires a
    > CPU
    > | > : memory clock ratio of 333 MHz / 200 MHz = 5 : 3
    > | >
    > | > (Since there is no CPU : memory clock ratio between 4 : 3 and 5 : 3 you
    > must
    > | > use the 5 : 3 ratio for overclocking to 3.0 GHz)
    > | >
    > | > Memory can also be overclocked. You may find that the PC6400 memory
    > will
    > | > operate at with a clock speed of more than 200 MHz, and that you can
    > | > overclock the E6600 to more than 3.2 GHz with a CPU : memory clock ratio
    > of
    > | > 5 : 3 and a FSB clock of more than 333 MHz.
    > | >
    > | > Phil Weldon
    > | >
    > | > "Nick Le Lievre" <> wrote in
    > messagenews:4612673b$0$21944$...
    > | > | "Phil Weldon" <> wrote in message
    > | > |news:7NQPh.17140$...
    > | > | >
    > | > | > If the motherboard uses DDR2 memory, to get a CPU clock rate for
    > your
    > | > | > E6600
    > | > | > you either must have DDR2 memory that will work at PC10600 rates, OR
    > you
    > | > | > must use a CPU:memory ratio that brings the memory clock down to
    > | > whatever
    > | > | > speed you CAN get out of your memory.
    > | > | >
    > | > |
    > | > | So if I want to get 333 * 9 out of my mates E6600 I would need PC10600
    > | > DDR2
    > | > | memory... he has DDR2 6400. Therefore what CPU:Memory ratio should I
    > use?
    > | > |
    > | > |
    > |
    > | Phil, sorry to intervene but you seem to forget that for DDR2 memory
    > | the bus clock is twice the mem clock. As a consequence, the clock you
    > | must use to get PC6400 (DDR2 800) mem to stock speed is 400 MHz, not
    > | 200.
    > | So, to have a 1:1 ratio with the E6600 at 3Ghz (333 MHz * 9) , you
    > | only have to use DDR2 667 chips (PC5300 modules). No need to search
    > | for PC10600 modules.
    > | This is exactly what I am using in my PC now.
    > |


    Where you make an error is in using the mem internal memory clock to
    do your calculations. For DDR2 memory, the bus clock has to be twice
    the mem clock. That's how DDR2 communicates 4 data per mem clock
    pulse.
    Your calculations are correct for DDR (not 2) mem however.
    So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    bus to the mem has to be at 400 MHz to have stock speed.
    In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    As reported by both the BIOS and by CPU-Z.
    And the very high speed mem modules (PC8500 etc) are, I think, only
    intended for very agressive overclocking fans up to now.

    PS: I know about the e-mail problem, however google does not allow me
    to use a fake address of any kind. Or maybe you can tell me howto?
     
  10. Never mind, posting from newsgroup now.
     
  11. Phil Weldon

    Phil Weldon Guest

    'mcarleer' wrote, in part:
    | Where you make an error is in using the mem internal memory clock to
    | do your calculations. For DDR2 memory, the bus clock has to be twice
    | the mem clock. That's how DDR2 communicates 4 data per mem clock
    | pulse.
    | Your calculations are correct for DDR (not 2) mem however.
    | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    | bus to the mem has to be at 400 MHz to have stock speed.
    | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    | As reported by both the BIOS and by CPU-Z.
    | And the very high speed mem modules (PC8500 etc) are, I think, only
    | intended for very agressive overclocking fans up to now.
    _____

    Regardless of the numbers and divisors used, the case remains that DDR2
    PC6400 memory cannot use a 1:1 CPU clock : memory clock ratio if the FSB is
    1066 (unless it is overclocked beyond manufacturer specifications It can
    run at a 1:1 ratio with an FSB of 800 MHz. DDR2 PC1066 CAN run at specified
    speed with an FSB of 1066 MHz and a 1:1 CPU clock : memory clock ratio. The
    double clocked DDR2 memory will work off the same clock as the CPU; 266 MHz
    in the case of a 1066 MHz FSB. THe FSB speed will be the same as the memory
    speed.

    There is probably a much more clear way of stating this, but that's the best
    O cam do from my present understanding.

    Phil Weldon

    <> wrote in message
    news:...
    ..
    ..|
    | Where you make an error is in using the mem internal memory clock to
    | do your calculations. For DDR2 memory, the bus clock has to be twice
    | the mem clock. That's how DDR2 communicates 4 data per mem clock
    | pulse.
    | Your calculations are correct for DDR (not 2) mem however.
    | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    | bus to the mem has to be at 400 MHz to have stock speed.
    | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    | As reported by both the BIOS and by CPU-Z.
    | And the very high speed mem modules (PC8500 etc) are, I think, only
    | intended for very agressive overclocking fans up to now.
    |
    | PS: I know about the e-mail problem, however google does not allow me
    | to use a fake address of any kind. Or maybe you can tell me howto?
    |
     
  12. I agree totally that PC6400 modules cannot run at a 1:1 ratio with an FSB of
    1066 MHz.
    A DDR2 mem module running at 266MHz bus speed (133 MHz internal), however,
    is DDR2 533 (PC4200). Not DDR2 1066. That is the definition.
    A P5W DH mobo with a C2D E6600 (266 MHz clock, 9 x multiplier) will run by
    default mem modules as if they were DDR2 533 even if they are DDR2 800, DDR2
    1066 or whatever. Just to stick to the 1:1 ratio.
    With an E6600 CPU at stock speed (266 MHz x 9 = 2.4 GHz), using mems faster
    than DDR2 533 (PC4200) with ratios other than 1:1 to run the mem at their
    stock speed does not improve the data bandwidth at all. It even, in some
    instances, lowers the bandwidth. Simply because the CPU, anyway, cannot send
    or receive data at a higher pace than its running speed. This has been
    proven by very thorough benchmarks available on the net.
    Where it becomes interesting to use higher speed memories is when
    overclocking the CPU. For example, I am overclocking my E6600 at 333 MHz x 9
    = 3.0 GHz. To retain the 1:1 ratio, I have to use DDR2 667 (PC5300) modules.
    On the other hand, speedier mems can run at a DDR2 533 clock speed with far
    lower latencies.
    If using a DDR2 533 at 266 MHz bus speed (133 MHz internal), you will
    probably have to use 5-5-5-15 timings, whereas using DDR2 1066 at the same
    266 MHz bus speed, you will probably be able to use 3-3-3-12, or even
    2-2-2-12 timings. And this brings a substantial data bandwidth enhancement.
    Remember: a DDR2 XXX (PCXXX * 8) runs at an internal clock frequency of
    XXX/4, but communicates with the bus at XXX/2. And this XXX/2 has to be the
    clock frequency fed to the CPU to have a 1:1 ratio.

    "Phil Weldon" <> wrote in message
    news:t7ZVh.3366$...
    > 'mcarleer' wrote, in part:
    > | Where you make an error is in using the mem internal memory clock to
    > | do your calculations. For DDR2 memory, the bus clock has to be twice
    > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    > | pulse.
    > | Your calculations are correct for DDR (not 2) mem however.
    > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    > | bus to the mem has to be at 400 MHz to have stock speed.
    > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    > | As reported by both the BIOS and by CPU-Z.
    > | And the very high speed mem modules (PC8500 etc) are, I think, only
    > | intended for very agressive overclocking fans up to now.
    > _____
    >
    > Regardless of the numbers and divisors used, the case remains that DDR2
    > PC6400 memory cannot use a 1:1 CPU clock : memory clock ratio if the FSB

    is
    > 1066 (unless it is overclocked beyond manufacturer specifications It can
    > run at a 1:1 ratio with an FSB of 800 MHz. DDR2 PC1066 CAN run at

    specified
    > speed with an FSB of 1066 MHz and a 1:1 CPU clock : memory clock ratio.

    The
    > double clocked DDR2 memory will work off the same clock as the CPU; 266

    MHz
    > in the case of a 1066 MHz FSB. THe FSB speed will be the same as the

    memory
    > speed.
    >
    > There is probably a much more clear way of stating this, but that's the

    best
    > O cam do from my present understanding.
    >
    > Phil Weldon
    >
    > <> wrote in message
    > news:...
    > .
    > .|
    > | Where you make an error is in using the mem internal memory clock to
    > | do your calculations. For DDR2 memory, the bus clock has to be twice
    > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    > | pulse.
    > | Your calculations are correct for DDR (not 2) mem however.
    > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    > | bus to the mem has to be at 400 MHz to have stock speed.
    > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    > | As reported by both the BIOS and by CPU-Z.
    > | And the very high speed mem modules (PC8500 etc) are, I think, only
    > | intended for very agressive overclocking fans up to now.
    > |
    > | PS: I know about the e-mail problem, however google does not allow me
    > | to use a fake address of any kind. Or maybe you can tell me howto?
    > |
    >
    >
     
  13. Ed Medlin

    Ed Medlin Guest

    "Phil Weldon" <> wrote in message
    news:t7ZVh.3366$...
    > 'mcarleer' wrote, in part:
    > | Where you make an error is in using the mem internal memory clock to
    > | do your calculations. For DDR2 memory, the bus clock has to be twice
    > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    > | pulse.
    > | Your calculations are correct for DDR (not 2) mem however.
    > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    > | bus to the mem has to be at 400 MHz to have stock speed.
    > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    > | As reported by both the BIOS and by CPU-Z.
    > | And the very high speed mem modules (PC8500 etc) are, I think, only
    > | intended for very agressive overclocking fans up to now.
    > _____
    >
    > Regardless of the numbers and divisors used, the case remains that DDR2
    > PC6400 memory cannot use a 1:1 CPU clock : memory clock ratio if the FSB
    > is
    > 1066 (unless it is overclocked beyond manufacturer specifications It can
    > run at a 1:1 ratio with an FSB of 800 MHz. DDR2 PC1066 CAN run at
    > specified
    > speed with an FSB of 1066 MHz and a 1:1 CPU clock : memory clock ratio.
    > The
    > double clocked DDR2 memory will work off the same clock as the CPU; 266
    > MHz
    > in the case of a 1066 MHz FSB. THe FSB speed will be the same as the
    > memory
    > speed.
    >
    > There is probably a much more clear way of stating this, but that's the
    > best
    > O cam do from my present understanding.
    >
    > Phil Weldon
    >

    The way I understand it with today's MB bios, is that since the memory
    and CPU run seperate of each other the bios will read the spd from the
    memory and set it to default. So if you are running DDR2 800 along with an
    E6600 the memory will default to 800 which will not affect the CPU speed,
    but will affect memory performance a bit. Most, but not all memory will have
    some OC overhead. That is why I went with faster rated memory (PC1066) for
    the E6600 for just a little more overhead to run at 1:1.......I hope...:).

    Ed
     
  14. Well, this is apparently not how the Asus P5W DH (AMIBIOS 1407 or 1901)
    behaves. It seems to always favor the 1:1 ratio between CPU and mem clock
    when set in Auto mode, which comes as default. But you can change it
    manually in the BIOS.
    And if you look at the spd data of the Corsair DDR2 667 value select sticks
    which I use, it gives the timings for 667, 533 and 400. At least, that's
    what CPU-Z mentions.
    As I mentionned earlier, using higher speed DDR2 enables you either to
    overclock the CPU and still stay with the 1:1 ratio, or reduce substantially
    the latency timings if you run the mem at a lower than specified speed. Or a
    combination of both.

    "Ed Medlin" <> wrote in message
    news:1D2Wh.1370$...
    >
    > "Phil Weldon" <> wrote in message
    > news:t7ZVh.3366$...
    > > 'mcarleer' wrote, in part:
    > > | Where you make an error is in using the mem internal memory clock to
    > > | do your calculations. For DDR2 memory, the bus clock has to be twice
    > > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    > > | pulse.
    > > | Your calculations are correct for DDR (not 2) mem however.
    > > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    > > | bus to the mem has to be at 400 MHz to have stock speed.
    > > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    > > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    > > | As reported by both the BIOS and by CPU-Z.
    > > | And the very high speed mem modules (PC8500 etc) are, I think, only
    > > | intended for very agressive overclocking fans up to now.
    > > _____
    > >
    > > Regardless of the numbers and divisors used, the case remains that DDR2
    > > PC6400 memory cannot use a 1:1 CPU clock : memory clock ratio if the FSB
    > > is
    > > 1066 (unless it is overclocked beyond manufacturer specifications It

    can
    > > run at a 1:1 ratio with an FSB of 800 MHz. DDR2 PC1066 CAN run at
    > > specified
    > > speed with an FSB of 1066 MHz and a 1:1 CPU clock : memory clock ratio.
    > > The
    > > double clocked DDR2 memory will work off the same clock as the CPU; 266
    > > MHz
    > > in the case of a 1066 MHz FSB. THe FSB speed will be the same as the
    > > memory
    > > speed.
    > >
    > > There is probably a much more clear way of stating this, but that's the
    > > best
    > > O cam do from my present understanding.
    > >
    > > Phil Weldon
    > >

    > The way I understand it with today's MB bios, is that since the memory
    > and CPU run seperate of each other the bios will read the spd from the
    > memory and set it to default. So if you are running DDR2 800 along with an
    > E6600 the memory will default to 800 which will not affect the CPU speed,
    > but will affect memory performance a bit. Most, but not all memory will

    have
    > some OC overhead. That is why I went with faster rated memory (PC1066) for
    > the E6600 for just a little more overhead to run at 1:1.......I

    hope...:).
    >
    > Ed
    >
    >
     
  15. Fishface

    Fishface Guest

    Ed Medlin wrote:
    > Most, but not all memory will have some OC overhead. That is why
    > I went with faster rated memory (PC1066) for the E6600 for just a
    > little more overhead to run at 1:1.......I hope...:).


    Yup, I'd say you're pretty much covered-- you might even have to
    drop the multiplier a tad!
     
  16. > Most, but not all memory will have
    > some OC overhead. That is why I went with faster rated memory (PC1066) for
    > the E6600 for just a little more overhead to run at 1:1.......I

    hope...:).
    >
    > Ed
    >
    >

    Well, to run your DDR2 1066 at stock speed and at 1:1 ratio, your E6600
    clock should be 533 MHz.
    With the normal 9 times multiplier, it means your CPU will be overclocked at
    4.8 GHz.
    Better use liquid nitrogen to cool the beast. :) :)
    Of course, you may lower the CPU multiplier value to 6 which will give a
    more reasonable 3.2 GHZ.
    Or just underclock the mem and use more agressive latency timings.
    Now, I am not even sure you will be able to run the E6600 with a 533 MHz
    clock.
    From what I read, people usually cannot go higher than ~ 450 MHz. I am not
    sure if this is a CPU, chipset or FSB limit.
     
  17. Phil Weldon

    Phil Weldon Guest

    'M. R. Carleer' wrote, in part:
    | A DDR2 mem module running at 266MHz bus speed (133 MHz internal), however,
    | is DDR2 533 (PC4200). Not DDR2 1066. That is the definition.
    | A P5W DH mobo with a C2D E6600 (266 MHz clock, 9 x multiplier) will run by
    | default mem modules as if they were DDR2 533 even if they are DDR2 800,
    DDR2
    | 1066 or whatever. Just to stick to the 1:1 ratio.
    | With an E6600 CPU at stock speed (266 MHz x 9 = 2.4 GHz), using mems
    faster
    | than DDR2 533 (PC4200) with ratios other than 1:1 to run the mem at their
    | stock speed does not improve the data bandwidth at all. It even, in some
    | instances, lowers the bandwidth. Simply because the CPU, anyway, cannot
    send
    | or receive data at a higher pace than its running speed. This has been
    | proven by very thorough benchmarks available on the net.
    | Where it becomes interesting to use higher speed memories is when
    | overclocking the CPU. For example, I am overclocking my E6600 at 333 MHz x
    9
    | = 3.0 GHz. To retain the 1:1 ratio, I have to use DDR2 667 (PC5300)
    modules.
    _____

    Beg to differ. The CPU stock clock speed for the E6600 is 266 MHz giving a
    an FSB of 1066 MHz. To use a 1:1 CPU clock : memory clock ratio REQUIRES
    PC1066 (PC8500) DDR2 memory. The P1066 rating is based on a 4 X 266 MHz =
    1066 MHz FSB. The advantage of DDR2 is NOT that it runs at a double clock
    rate compared to DDR memory; THAT advantage is nullified by the INTERNAL to
    the memory chip division of the clock rate by two. The advantage is that
    DDR2 can run at higher EXTERNAL clock speeds (and at lower power.) Thus, to
    operate with the EXTERNAL memory clock at 266 MHz requires DDR2 memory that
    has DDR2 PC1066 performance. When overclocking an E6600, the FSB must be
    higher than 1066 MHz (266 MHz clock rate). In this case, to use a 1:1 CPU
    clock : memory clock ratio requires DDR2 memory that has greater than PC1066
    performance. DDR2 PC533 performance memory requires a 2:1 CPU clock :
    memory clock ratio.

    Phil Weldon

    "M. R. Carleer" <> wrote in message
    news:f0a083$96g$...
    |I agree totally that PC6400 modules cannot run at a 1:1 ratio with an FSB
    of
    | 1066 MHz.
    | A DDR2 mem module running at 266MHz bus speed (133 MHz internal), however,
    | is DDR2 533 (PC4200). Not DDR2 1066. That is the definition.
    | A P5W DH mobo with a C2D E6600 (266 MHz clock, 9 x multiplier) will run by
    | default mem modules as if they were DDR2 533 even if they are DDR2 800,
    DDR2
    | 1066 or whatever. Just to stick to the 1:1 ratio.
    | With an E6600 CPU at stock speed (266 MHz x 9 = 2.4 GHz), using mems
    faster
    | than DDR2 533 (PC4200) with ratios other than 1:1 to run the mem at their
    | stock speed does not improve the data bandwidth at all. It even, in some
    | instances, lowers the bandwidth. Simply because the CPU, anyway, cannot
    send
    | or receive data at a higher pace than its running speed. This has been
    | proven by very thorough benchmarks available on the net.
    | Where it becomes interesting to use higher speed memories is when
    | overclocking the CPU. For example, I am overclocking my E6600 at 333 MHz x
    9
    | = 3.0 GHz. To retain the 1:1 ratio, I have to use DDR2 667 (PC5300)
    modules.
    | On the other hand, speedier mems can run at a DDR2 533 clock speed with
    far
    | lower latencies.
    | If using a DDR2 533 at 266 MHz bus speed (133 MHz internal), you will
    | probably have to use 5-5-5-15 timings, whereas using DDR2 1066 at the same
    | 266 MHz bus speed, you will probably be able to use 3-3-3-12, or even
    | 2-2-2-12 timings. And this brings a substantial data bandwidth
    enhancement.
    | Remember: a DDR2 XXX (PCXXX * 8) runs at an internal clock frequency of
    | XXX/4, but communicates with the bus at XXX/2. And this XXX/2 has to be
    the
    | clock frequency fed to the CPU to have a 1:1 ratio.
    |
    | "Phil Weldon" <> wrote in message
    | news:t7ZVh.3366$...
    | > 'mcarleer' wrote, in part:
    | > | Where you make an error is in using the mem internal memory clock to
    | > | do your calculations. For DDR2 memory, the bus clock has to be twice
    | > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    | > | pulse.
    | > | Your calculations are correct for DDR (not 2) mem however.
    | > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    | > | bus to the mem has to be at 400 MHz to have stock speed.
    | > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    | > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    | > | As reported by both the BIOS and by CPU-Z.
    | > | And the very high speed mem modules (PC8500 etc) are, I think, only
    | > | intended for very agressive overclocking fans up to now.
    | > _____
    | >
    | > Regardless of the numbers and divisors used, the case remains that DDR2
    | > PC6400 memory cannot use a 1:1 CPU clock : memory clock ratio if the FSB
    | is
    | > 1066 (unless it is overclocked beyond manufacturer specifications It
    can
    | > run at a 1:1 ratio with an FSB of 800 MHz. DDR2 PC1066 CAN run at
    | specified
    | > speed with an FSB of 1066 MHz and a 1:1 CPU clock : memory clock ratio.
    | The
    | > double clocked DDR2 memory will work off the same clock as the CPU; 266
    | MHz
    | > in the case of a 1066 MHz FSB. THe FSB speed will be the same as the
    | memory
    | > speed.
    | >
    | > There is probably a much more clear way of stating this, but that's the
    | best
    | > O cam do from my present understanding.
    | >
    | > Phil Weldon
    | >
    | > <> wrote in message
    | > news:...
    | > .
    | > .|
    | > | Where you make an error is in using the mem internal memory clock to
    | > | do your calculations. For DDR2 memory, the bus clock has to be twice
    | > | the mem clock. That's how DDR2 communicates 4 data per mem clock
    | > | pulse.
    | > | Your calculations are correct for DDR (not 2) mem however.
    | > | So, a DDR2 800 mem (PC6400) uses an internal clock of 200 MHz, but the
    | > | bus to the mem has to be at 400 MHz to have stock speed.
    | > | In my case a C2D E6600 (oveclocked at 333 MHz x 9 = 3 GHz) on a P5W DH
    | > | is happily running with 2 sticks of DDR2 667 (PC5300) at a 1:1 ratio.
    | > | As reported by both the BIOS and by CPU-Z.
    | > | And the very high speed mem modules (PC8500 etc) are, I think, only
    | > | intended for very agressive overclocking fans up to now.
    | > |
    | > | PS: I know about the e-mail problem, however google does not allow me
    | > | to use a fake address of any kind. Or maybe you can tell me howto?
    | > |
    | >
    | >
    |
    |
     
  18. Thomas

    Thomas Guest

    Phil Weldon wrote:
    > 'M. R. Carleer' wrote, in part:
    > > A DDR2 mem module running at 266MHz bus speed (133 MHz internal),
    > > however, is DDR2 533 (PC4200). Not DDR2 1066. That is the
    > > definition.
    > > A P5W DH mobo with a C2D E6600 (266 MHz clock, 9 x multiplier) will
    > > run by default mem modules as if they were DDR2 533 even if they
    > > are DDR2 800, DDR2 1066 or whatever. Just to stick to the 1:1 ratio.
    > > With an E6600 CPU at stock speed (266 MHz x 9 = 2.4 GHz), using
    > > mems faster than DDR2 533 (PC4200) with ratios other than 1:1 to
    > > run the mem at their stock speed does not improve the data
    > > bandwidth at all. It even, in some instances, lowers the bandwidth.
    > > Simply because the CPU, anyway, cannot send or receive data at a
    > > higher pace than its running speed. This has been proven by very
    > > thorough benchmarks available on the net.
    > > Where it becomes interesting to use higher speed memories is when
    > > overclocking the CPU. For example, I am overclocking my E6600 at
    > > 333 MHz x 9 = 3.0 GHz. To retain the 1:1 ratio, I have to use DDR2
    > > 667 (PC5300)

    > modules.
    > _____
    >
    > Beg to differ. The CPU stock clock speed for the E6600 is 266 MHz
    > giving a an FSB of 1066 MHz. To use a 1:1 CPU clock : memory clock
    > ratio REQUIRES PC1066 (PC8500) DDR2 memory. The P1066 rating is
    > based on a 4 X 266 MHz = 1066 MHz FSB. The advantage of DDR2 is NOT
    > that it runs at a double clock rate compared to DDR memory; THAT
    > advantage is nullified by the INTERNAL to the memory chip division of
    > the clock rate by two. The advantage is that DDR2 can run at higher
    > EXTERNAL clock speeds (and at lower power.) Thus, to operate with
    > the EXTERNAL memory clock at 266 MHz requires DDR2 memory that has
    > DDR2 PC1066 performance. When overclocking an E6600, the FSB must be
    > higher than 1066 MHz (266 MHz clock rate). In this case, to use a
    > 1:1 CPU clock : memory clock ratio requires DDR2 memory that has
    > greater than PC1066 performance. DDR2 PC533 performance memory
    > requires a 2:1 CPU clock : memory clock ratio.


    Phil,

    Aren't you forgetting we're running dual-channel memory here? That means
    that the total data bandwidth of the memory is multiplied by two. So using 2
    bars of PC533 memory gives you PC1066 performance, enough to keep up with
    the 1066 MHz FSB of the E6 series. I actually can remember reading, one day
    after I finalized my order of 800 MHz DDR2, that for the E4300, 800 MHz DDR
    is nonsense, because to reach the 800 MHz bandwidth, you need to have an OC
    of 100%, which is achieved only rarely and then with exotic cooling.

    I mean, if 1066 memory would be required to get the full performance out of
    stock clocked CPU's, I think that this would be the standard combination
    sold, but all standard PC's are sold with 533...

    Gosh this memory discussion is incredible, how difficult can they make it
    :)

    --
    Met vriendelijke groeten, Thomas vd Horst.
     
  19. Amir Facade

    Amir Facade Guest

    "Thomas" <> wrote in message
    news:4629cc10$0$29567$...
    > Phil Weldon wrote:
    >> 'M. R. Carleer' wrote, in part:
    >> > A DDR2 mem module running at 266MHz bus speed (133 MHz internal),
    >> > however, is DDR2 533 (PC4200). Not DDR2 1066. That is the
    >> > definition.
    >> > A P5W DH mobo with a C2D E6600 (266 MHz clock, 9 x multiplier) will
    >> > run by default mem modules as if they were DDR2 533 even if they
    >> > are DDR2 800, DDR2 1066 or whatever. Just to stick to the 1:1 ratio.
    >> > With an E6600 CPU at stock speed (266 MHz x 9 = 2.4 GHz), using
    >> > mems faster than DDR2 533 (PC4200) with ratios other than 1:1 to
    >> > run the mem at their stock speed does not improve the data
    >> > bandwidth at all. It even, in some instances, lowers the bandwidth.
    >> > Simply because the CPU, anyway, cannot send or receive data at a
    >> > higher pace than its running speed. This has been proven by very
    >> > thorough benchmarks available on the net.
    >> > Where it becomes interesting to use higher speed memories is when
    >> > overclocking the CPU. For example, I am overclocking my E6600 at
    >> > 333 MHz x 9 = 3.0 GHz. To retain the 1:1 ratio, I have to use DDR2
    >> > 667 (PC5300)

    >> modules.
    >> _____
    >>
    >> Beg to differ. The CPU stock clock speed for the E6600 is 266 MHz
    >> giving a an FSB of 1066 MHz. To use a 1:1 CPU clock : memory clock
    >> ratio REQUIRES PC1066 (PC8500) DDR2 memory. The P1066 rating is
    >> based on a 4 X 266 MHz = 1066 MHz FSB. The advantage of DDR2 is NOT
    >> that it runs at a double clock rate compared to DDR memory; THAT
    >> advantage is nullified by the INTERNAL to the memory chip division of
    >> the clock rate by two. The advantage is that DDR2 can run at higher
    >> EXTERNAL clock speeds (and at lower power.) Thus, to operate with
    >> the EXTERNAL memory clock at 266 MHz requires DDR2 memory that has
    >> DDR2 PC1066 performance. When overclocking an E6600, the FSB must be
    >> higher than 1066 MHz (266 MHz clock rate). In this case, to use a
    >> 1:1 CPU clock : memory clock ratio requires DDR2 memory that has
    >> greater than PC1066 performance. DDR2 PC533 performance memory
    >> requires a 2:1 CPU clock : memory clock ratio.

    >
    > Phil,
    >
    > Aren't you forgetting we're running dual-channel memory here? That means
    > that the total data bandwidth of the memory is multiplied by two. So using
    > 2 bars of PC533 memory gives you PC1066 performance, enough to keep up
    > with the 1066 MHz FSB of the E6 series. I actually can remember reading,
    > one day after I finalized my order of 800 MHz DDR2, that for the E4300,
    > 800 MHz DDR is nonsense, because to reach the 800 MHz bandwidth, you need
    > to have an OC of 100%, which is achieved only rarely and then with exotic
    > cooling.
    >
    > I mean, if 1066 memory would be required to get the full performance out
    > of stock clocked CPU's, I think that this would be the standard
    > combination sold, but all standard PC's are sold with 533...
    >
    > Gosh this memory discussion is incredible, how difficult can they make it
    > :)
    >
    > --
    > Met vriendelijke groeten, Thomas vd Horst.
    >

    OMG
    I thought I was confused before!

    Amir
     

  20. > Beg to differ. The CPU stock clock speed for the E6600 is 266 MHz giving
    > a
    > an FSB of 1066 MHz. To use a 1:1 CPU clock : memory clock ratio REQUIRES
    > PC1066 (PC8500) DDR2 memory. The P1066 rating is based on a 4 X 266 MHz =
    > 1066 MHz FSB. The advantage of DDR2 is NOT that it runs at a double clock
    > rate compared to DDR memory; THAT advantage is nullified by the INTERNAL
    > to
    > the memory chip division of the clock rate by two. The advantage is that
    > DDR2 can run at higher EXTERNAL clock speeds (and at lower power.) Thus,
    > to
    > operate with the EXTERNAL memory clock at 266 MHz requires DDR2 memory
    > that
    > has DDR2 PC1066 performance. When overclocking an E6600, the FSB must be
    > higher than 1066 MHz (266 MHz clock rate). In this case, to use a 1:1 CPU
    > clock : memory clock ratio requires DDR2 memory that has greater than
    > PC1066
    > performance. DDR2 PC533 performance memory requires a 2:1 CPU clock :
    > memory clock ratio.
    >
    > Phil Weldon

    OK Phil, go and have a look at this page please:

    http://en.wikipedia.org/wiki/DDR2_SDRAM

    In order to have a 1:1 ratio, the CPU clock has to be the same as the Mem
    I/O clock.
    And let me explain the difference between the different memory types:

    SDRAM: one piece of data is sent/received per I/O clock pulse. Mem clock =
    I/O clock.=> 1 piece of data per Mem clock pulse.

    DDR (double data rate) SDRAM: one piece of data is sent/received at the
    rising edge of the I/O clock pulse, and a second one at the falling edge.
    Mem clock = I/O clock. => 2 pieces of data per Mem clock pulse.

    DDR2 (quad data rate) SDRAM: one piece of data is sent/received at the
    rising edge of the I/O clock pulse, and another one at the falling edge.
    BUT: I/O clock = 2 * Mem clock. => 4 pieces of data per Mem clock pulse.

    With my E6600 overclocked at 3.0 GHz, the CPU clock speed is 333 MHz (* 9
    multiplier = 3.0 GHz, you know).
    If I want to have a 1:1 ratio, I have to use memory sticks with a 333 MHz
    I/O bus clock. These are DDR2 667 memories, also called PC5300 modules.
    And when using PC5300 (DDR2 667) Corsair Value Select modules at their stock
    speed, this is exactly what the BIOS of my mobo and CPU-Z tell me: a 1:1
    ratio.
    And yes, in these conditions, the FSB value is 1333.
    When using the E6600 at stock speed (266 MHz, 2.4 GHz internal), no need to
    go with sticks faster than PC4200 (DDR2 533).
    So, once again, no need at all to use DDR2 1066. That's two times faster
    than needed. And the reason is that DDR2 sends/receives data at 4 times the
    mem clock speed, because the DDR2 I/O interface circuitry works at twice the
    internal mem frequency.
     
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