GA-7VRXP: rev. 1.0 or 2.0? And FSB 333?

Discussion in 'Gigabyte' started by Mike, Apr 15, 2004.

  1. Mike

    Kevin Lawton Guest

    || I felt it worthwhile pointing out that the CPU FSB clock rate and
    || the memory bus clock rate are different things, as some newsgroup
    || posters seem to confuse the two. Fortunately, on the GA-7VRXP they
    || can be set independently.
    |
    | OK. So to conclude we have a FSB or system bus speed that runs on
    | either 100 or 133 MHz which can be selected at the board with a
    | switch. We have a memory bus that runs on 100, 133, or 166 MHz which
    | can be selected through the BIOS. And we have a CPU clock speed that
    | can be adjusted through the BIOS from 133 to at least 166 MHz. Am I
    | right?
    |
    | And a FSB of 166 is simply not possible without alteration of the
    | board, right?

    Correct on all points, except that you are making a distinction between the
    processor clock and the FSB clock - they are the same thing ! That is why I
    describe it as the 'CPU FSB' clock. And yes, it can be set to run at either
    100 MHz or 133 MHz on a GA-7VRXP.
    Looking at it from a different angle:
    The motherboard 'northbridge' chip includes a memory management function and
    thus sits logically between the CPU and the memory. The northbridge has two
    sides: the side which communicates with the CPU is known as the 'front'
    side, so the data bus between CPU and northbridge is known as the 'front
    side bus' - ie: FSB. There is a limit to the speed any particular CPU can
    have its FSB clocked at, and there is also a limit to what speed a
    northbridge chip can have the FSB clocked at. If you attempt to run the FSB
    faster than these limits then you are 'overclocking' it which might cause
    problems. On the GA-7VRXP you can only set the FSB clock to 100 or 133 MHz.
    Bear in mind that due to a technology known as double-data-rate (DDR) data
    will be strobed through the bus on both the leading and trailing edges of
    the FSB clock signal, so the maximum data rate will be 266 MHz (2 x 133
    MHz).
    There is also a limit to what speed any particular type of memory can be run
    at. The 'memory side' of the northbridge chip is connected to the memory on
    the memory bus (the DMA controller also uses this bus, but that is another
    matter) and data is strobed on the memory bus by the memory clock. When
    setting the memory clock speed the limitations of the memory and the
    northbridge chip have to be taken into account. The VIA KT333 northbridge
    chip on the GA-7VRXP can manage a top memory data rate of 333 MHz. DDR is
    used on this bus, so the memory bus clock speed is set at half the DDR
    rate - 166 MHz maximum, or 133 MHz or 100 MHz if you have slower memory -
    via a BIOS setting.
    A particular advantage of modern northbridge chips like the VIA KT333 is
    that they can run their front side bus and memory bus at different speeds.
    That is why you have two settings.
    The CPU speed is the frequency the CPU is clocked at. This is dependent on
    the capabilities of the CPU used - for example, an XP2400 CPU is specified
    as working at 2.0 GHz. Run it faster than this and you are 'overclocking'
    it. It might work, but AMD don't guarantee that it will. The CPU speed is
    derrived as a multiple of the FSB clock speed, and can be varied on the
    GA-7VRXP by means of a bank of switches. To be honest, unless you actually
    want to over-clock the processor - or need to under-clock it for some
    reason, it is best to leave the 'multiplier' switches on the default 'auto'
    setting.
    Kevin.
     
    Kevin Lawton, May 4, 2004
    #21
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  2. Mike

    Raju Guest

    according to gigabyte website there is a rev 3 board...
    http://www.giga-byte.com/MotherBoard/Products/Products_GA-7VRXP (Rev 3.0
    ).htm
     
    Raju, May 4, 2004
    #22
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  3. Mike

    Mike Guest

    | OK. So to conclude we have a FSB or system bus speed that runs on
    But as I was saying, you CAN set the CPU clock speed = FSB manually in the BIOS!
    For sure! So we CAN adjust the FSB speed, right?

    Mike
     
    Mike, May 4, 2004
    #23
  4. Mike

    Kevin Lawton Guest

    | |||| Some of my systems use the GA-7VRXP Rev 2.0, and they do not appear
    |||| to have any way of setting the FSB clock to 166 MHz. On this board,
    |||| the FSB clock is set using a small on-board switch which selects
    |||| between 100 MHz or 133 MHz - there just isn't a 166 MHz option
    |||| available to use. The CPU clock multiplier is also set by on-board
    |||| switches, but that is another matter.
    |||
    ||| And I was thinking that when I use a CPU that runs on 166MHz the FSB
    ||| will automatically follow to 333. Am I right or wrong?
    |||
    |||| The processor FSB and the memory bus are different and set up
    |||| seperately -
    |||| it is important not to confuse the two.
    |||
    ||| Understood. But you are saying we cannot select a FSB or system bus
    ||| speed on the GA-7VRXP?
    ||
    || No - quite the opposite. You can select the CPU FSB clock speed via a
    || switch - either 100 MHz or 133 MHz, and you can select the memory
    || bus speed via the BIOS set-up - either 100 MHz, 133 MHz or 166 MHz.
    || That's what I said and that's how it is. I've used quite a few of
    || these boards recently and if Gigabyte have come out with a version
    || which will facilitate setting the CPU FSB clock higher than that
    || then I certainly haven't encountered it. Neither am I aware of any
    || 'Revision 3.0' or suchlike variant which might support a higher CPU
    || FSB clock rate.
    || It is also worth noting that these boards will only support DDR333
    || memory in two memory strips, and not three, whereas DDR200 and
    || DDR266 are supported in all three memory slots.
    || I felt it worthwhile pointing out that the CPU FSB clock rate and
    || the memory bus clock rate are different things, as some newsgroup
    || posters seem to confuse the two. Fortunately, on the GA-7VRXP they
    || can be set independently. Kevin.
    |
    | according to gigabyte website there is a rev 3 board...
    |
    http://www.giga-byte.com/MotherBoard/Products/Products_GA-7VRXP (Rev 3.0
    | ).htm

    Nice one, Raju, I wasn't aware of that. I am supposed to be sent bulletins
    of updates but that didn't come through !
    Judging by the spec, they seem to have to have altered just a few things for
    the Rev 3 version of the GA-7VRXP. The sound chip has changed and, most
    importantly, the FSB clock speed adjustment has changed from being an
    on-board switch to being set in the BIOS. The limitatons still seem to be
    the same , though, with a maximum 266 FSB (ie: 133 MHz clock) and only two
    strips of DDR333 memory supported (but three of DDR266 or DDR200). The CPU
    multiplier remains as on-board switches, too. I guess that this gives a bit
    more scope for pushing the board past its design limits - overclocking - if
    you really want to. I would still suggest that this is a good board for a
    thoroughbred-core CPU, but if you want to get the best out of a barton core
    then a different board would be more appropriate - the GA-7VAXP perhaps.
    Kevin.
     
    Kevin Lawton, May 4, 2004
    #24
  5. Kevin

    Thanks for the useful information in this and previous posts. So good
    I've saved extra copies for reference.

    Having followed your trials and tribulations in this (and other
    newsgroups) with installing W2K on a GA-7VRXP, did you ever resolve the
    problem?
     
    Simon Elliott, May 4, 2004
    #25
  6. Mike

    Kevin Lawton Guest

    | Kevin Lawton wrote:
    |
    || Nice one, Raju, I wasn't aware of that. I am supposed to be sent
    || bulletins of updates but that didn't come through !
    || Judging by the spec, they seem to have to have altered just a few
    || things for the Rev 3 version of the GA-7VRXP. The sound chip has
    || changed and, most importantly, the FSB clock speed adjustment has
    || changed from being an on-board switch to being set in the BIOS. The
    || limitatons still seem to be the same , though, with a maximum 266
    || FSB (ie: 133 MHz clock) and only two strips of DDR333 memory
    || supported (but three of DDR266 or DDR200). The CPU multiplier
    || remains as on-board switches, too. I guess that this gives a bit
    || more scope for pushing the board past its design limits -
    || overclocking - if you really want to. I would still suggest that
    || this is a good board for a thoroughbred-core CPU, but if you want to
    || get the best out of a barton core then a different board would be
    || more appropriate - the GA-7VAXP perhaps. Kevin.
    ||
    | Kevin
    |
    | Thanks for the useful information in this and previous posts. So good
    | I've saved extra copies for reference.
    |
    | Having followed your trials and tribulations in this (and other
    | newsgroups) with installing W2K on a GA-7VRXP, did you ever resolve
    | the problem?

    Not yet, Simon, but thanks for asking.
    The problem appears to revolve around the XP2400 processor, as when a Duron
    650 is fitted into the GA-7VRXP Windows 2000 behaves fine. But the
    combination is good with Linux, FreeBSD, BeOS or Windows Me so I'm thinking
    it might be a weakness in Windows 2000.
    Latest plan is to progressively upgrade through the Windows 2000 service
    packs, using the Duron 650 to get them installed and then swap over to the
    XP2400 to see if it will work - I've just not had time yet, that's all. If
    that doesn't work, then I'll probably have to purchase another XP2400 just
    to eliminate that as the culprit. I'm pretty disgusted at Microsoft for not
    providing better diagnostics or at least some sort of help.
    Open to any good ideas, of course.
    Kevin.
     
    Kevin Lawton, May 4, 2004
    #26
  7. "Open to any good ideas, of course."

    If I get any I'll shout, but it seemed like you'd tried just about anything I could think of. From what I recall you've isolated just about every other cause.

    A shame, 'cause as I said before, W2K works fine with my XP1600/GA-7VRXP combo.
     
    Simon Elliott, May 5, 2004
    #27
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