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Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLIReadyCrossFire Ready 80 PLUS Certif

Discussion in 'Intel' started by Yousuf Khan, Dec 14, 2010.

  1. Yousuf Khan

    Yousuf Khan Guest

    On 10-12-14 10:47 AM, Ant wrote:
    > Hello.
    >
    > http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005 -- I
    > noticed the price is cheap, but is that PSU good to get? NewEgg shows
    > high ratings. I wonder why so cheap. Bad batch?
    >
    > This is for my upcoming computer upgrade, over my current primary PC as
    > shown in http://zimage.com/~ant/antfarm/about/computers.txt , during my
    > Christmas break:
    > - Intel i7 950 CPU -- http://ark.intel.com/Product.aspx?id=37150
    > - Motherboard/Mobo. (GIGABYTE GA-X58A-UD3R [newer] or EVGA X58 FTW3
    > 132-GT-E768-KR [older])
    > - 6 GB of RAM)
    >
    > Thank you in advance. :)


    A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    was about 3+ years ago. These days the high end PSUs are putting out
    1000-1200W. So basically, much like processors, what used to be high-end
    before is now bargain-basement.

    I got a 650W PSU from Zalman myself, about 2 years ago, and I got it for
    much the same price, but that was on Ebay.

    Yousuf Khan

    PS-BTW, I corrected your newsgroup crosspost, it's
    "comp.sys.ibm.pc.hardware.chips" not "comp.sys.hardware.ibmpc". :)
     
    Yousuf Khan, Dec 14, 2010
    #1
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  2. Yousuf Khan

    Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sat, 18 Dec 2010 12:25:52 -0500, Yousuf Khan <>
    wrote:

    >On 12/15/2010 4:52 AM, Jim wrote:
    >> "Yousuf Khan" <> wrote in message
    >> news:4d079563$-lp.com...
    >> > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    >>> was about 3+ years ago. These days the high end PSUs are putting out
    >>> 1000-1200W. So basically, much like processors, what used to be
    >>> high-end before is now bargain-basement.

    >> Those kilowatt PSUs are only needed if your going SLI/Xfire. A single
    >> GPU system isn't likely to break 500watts.

    >
    >A GPU isn't the only thing that pushes a PSU. Hard drives are another
    >big draw.


    In usual installations 3-8W per drive isn't going to tax a 500W supply very
    hard.
     
    , Dec 18, 2010
    #2
    1. Advertising

  3. Yousuf Khan

    Bob Willard Guest

    On 12/18/2010 1:03 PM, zzzzzzzz wrote:
    > On Sat, 18 Dec 2010 12:25:52 -0500, Yousuf Khan<>
    > wrote:
    >
    >> On 12/15/2010 4:52 AM, Jim wrote:
    >>> "Yousuf Khan"<> wrote in message
    >>> news:4d079563$-lp.com...
    >>> > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    >>>> was about 3+ years ago. These days the high end PSUs are putting out
    >>>> 1000-1200W. So basically, much like processors, what used to be
    >>>> high-end before is now bargain-basement.
    >>> Those kilowatt PSUs are only needed if your going SLI/Xfire. A single
    >>> GPU system isn't likely to break 500watts.

    >>
    >> A GPU isn't the only thing that pushes a PSU. Hard drives are another
    >> big draw.

    >
    > In usual installations 3-8W per drive isn't going to tax a 500W supply very
    > hard.


    A few Watts of steady-state power drain is not much to worry about.
    But, for PS sizing, you need to consider the start-up which can be as
    much as 3A on the 12V rail per SATA HD. {And, for extremist PCs with
    RAID10 or RAID6 sets of 15K RPM SCSI HDs, it gets *really* serious.}
    --
    Cheers, Bob
     
    Bob Willard, Dec 18, 2010
    #3
  4. Yousuf Khan

    Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sat, 18 Dec 2010 13:38:00 -0500, Bob Willard
    <> wrote:

    >On 12/18/2010 1:03 PM, zzzzzzzz wrote:
    >> On Sat, 18 Dec 2010 12:25:52 -0500, Yousuf Khan<>
    >> wrote:
    >>
    >>> On 12/15/2010 4:52 AM, Jim wrote:
    >>>> "Yousuf Khan"<> wrote in message
    >>>> news:4d079563$-lp.com...
    >>>> > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    >>>>> was about 3+ years ago. These days the high end PSUs are putting out
    >>>>> 1000-1200W. So basically, much like processors, what used to be
    >>>>> high-end before is now bargain-basement.
    >>>> Those kilowatt PSUs are only needed if your going SLI/Xfire. A single
    >>>> GPU system isn't likely to break 500watts.
    >>>
    >>> A GPU isn't the only thing that pushes a PSU. Hard drives are another
    >>> big draw.

    >>
    >> In usual installations 3-8W per drive isn't going to tax a 500W supply very
    >> hard.

    >
    >A few Watts of steady-state power drain is not much to worry about.
    >But, for PS sizing, you need to consider the start-up which can be as
    >much as 3A on the 12V rail per SATA HD. {And, for extremist PCs with
    >RAID10 or RAID6 sets of 15K RPM SCSI HDs, it gets *really* serious.}


    SCSI sequences drives, doesn't it?
     
    , Dec 18, 2010
    #4
  5. Yousuf Khan

    willbill Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    Tue, 14 Dec 2010 08:19:58 -0800, Ant <> wrote:

    > Do I assume it will be fine for my upcoming system upgrade?


    Depends on what you want the PC to do; e.g. see:

    550W Roundup: Three PSUs at Different Prices
    by Martin Kaffei on 10/28/2010
    http://www.anandtech.com/show/3985/three-550w-psus-for-different-prices

    More recently and perhaps less on topic to you, you might also see:
    http://www.anandtech.com/show/3992/1000w1200w-highend-psuroundup
    ( 1000W-1200W Roundup: Five High-End PSUs )

    http://www.anandtech.com/show/4011/corsair-ax750-80plus-gold
    ( Corsair AX750 80 Plus Gold: Putting Corsair's Best to the Test )

    Bill
     
    willbill, Dec 18, 2010
    #5
  6. Yousuf Khan

    daytripper Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sat, 18 Dec 2010 16:58:50 -0600, ""
    <> wrote:

    >On Sat, 18 Dec 2010 13:38:00 -0500, Bob Willard
    ><> wrote:
    >
    >>On 12/18/2010 1:03 PM, zzzzzzzz wrote:
    >>> On Sat, 18 Dec 2010 12:25:52 -0500, Yousuf Khan<>
    >>> wrote:
    >>>
    >>>> On 12/15/2010 4:52 AM, Jim wrote:
    >>>>> "Yousuf Khan"<> wrote in message
    >>>>> news:4d079563$-lp.com...
    >>>>> > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    >>>>>> was about 3+ years ago. These days the high end PSUs are putting out
    >>>>>> 1000-1200W. So basically, much like processors, what used to be
    >>>>>> high-end before is now bargain-basement.
    >>>>> Those kilowatt PSUs are only needed if your going SLI/Xfire. A single
    >>>>> GPU system isn't likely to break 500watts.
    >>>>
    >>>> A GPU isn't the only thing that pushes a PSU. Hard drives are another
    >>>> big draw.
    >>>
    >>> In usual installations 3-8W per drive isn't going to tax a 500W supply very
    >>> hard.

    >>
    >>A few Watts of steady-state power drain is not much to worry about.
    >>But, for PS sizing, you need to consider the start-up which can be as
    >>much as 3A on the 12V rail per SATA HD. {And, for extremist PCs with
    >>RAID10 or RAID6 sets of 15K RPM SCSI HDs, it gets *really* serious.}

    >
    >SCSI sequences drives, doesn't it?


    That's a host adapter firmware feature that depends on drive support - but,
    yes, it's supported by SCSI, and SAS, and SATA as well. My old SCSI raid tower
    used it, and my current SATA array is using it now...

    /daytripper
     
    daytripper, Dec 19, 2010
    #6
  7. Yousuf Khan

    daytripper Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sat, 18 Dec 2010 12:25:52 -0500, Yousuf Khan <>
    wrote:

    >On 12/15/2010 4:52 AM, Jim wrote:
    >> "Yousuf Khan" <> wrote in message
    >> news:4d079563$-lp.com...
    >> > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    >>> was about 3+ years ago. These days the high end PSUs are putting out
    >>> 1000-1200W. So basically, much like processors, what used to be
    >>> high-end before is now bargain-basement.

    >> Those kilowatt PSUs are only needed if your going SLI/Xfire. A single
    >> GPU system isn't likely to break 500watts.

    >
    >A GPU isn't the only thing that pushes a PSU. Hard drives are another
    >big draw.
    >
    > Yousuf Khan


    Not even close. I have an ATI 5970 that will pull almost 300 watts - and can
    go from a low-power state to full-on watt-suckage mode in a heartbeat.

    The half-dozen 10K rpm hard drives and the SSD barely pull a tenth of that
    once they're all spun up. And with the cabinet using sequenced spin-up there's
    not much of a "thump" when powering up the drives.

    fwiw, Rosewill 1000W continuous 80 plus gold certified modular power supply
    with one big fat 12V rail feeding a 980x, that freaky 5970 and a bunch of
    storage - and is amazingly quiet doing it...

    /daytripper
     
    daytripper, Dec 19, 2010
    #7
  8. Yousuf Khan

    Rev.3.20 Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLIReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Dec 14, 9:03 am, Yousuf Khan <> wrote:
    > On 10-12-14 10:47 AM, Ant wrote:
    >
    > > Hello.

    >
    > >http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005-- I
    > > noticed the price is cheap, but is that PSU good to get? NewEgg shows
    > > high ratings. I wonder why so cheap. Bad batch?

    >
    > > This is for my upcoming computer upgrade, over my current primary PC as
    > > shown inhttp://zimage.com/~ant/antfarm/about/computers.txt, during my
    > > Christmas break:
    > > - Intel i7 950 CPU --http://ark.intel.com/Product.aspx?id=37150
    > > - Motherboard/Mobo. (GIGABYTE GA-X58A-UD3R [newer] or EVGA X58 FTW3
    > > 132-GT-E768-KR [older])
    > > - 6 GB of RAM)

    >
    > > Thank you in advance. :)

    >
    > A 650W PSU is hardly top of the line anymore. It's like what a 350W PSU
    > was about 3+ years ago. These days the high end PSUs are putting out
    > 1000-1200W. So basically, much like processors, what used to be high-end
    > before is now bargain-basement.
    >
    > I got a 650W PSU from Zalman myself, about 2 years ago, and I got it for
    > much the same price, but that was on Ebay.
    >
    >         Yousuf Khan
    >
    > PS-BTW, I corrected your newsgroup crosspost, it's
    > "comp.sys.ibm.pc.hardware.chips" not "comp.sys.hardware.ibmpc". :)


    Just a side note for others who may be considering a larger supply.
    For those of you building a box or just needing a supply keep in mind
    the bigger the supply i.e., the higher the output wattage then
    typically the more it costs to operate. If all you need is 350 watts
    of output power (typically plenty for business apps.) and you purchase
    a 1000+ watt supply then the added capacity is only generating heat
    and costing you money to cool and operate.

    Too many times people become wrapped around the axle sort of speak
    with numbers rather than actual requirements. A general rule of thumb
    for capacity is full load plus 125% for spikes and sustained
    operation. The same number is used when fusing AC circuits.Some may
    feel this is a bit conservative for general supply design but it
    provides plenty of overhead.

    Remember heat kills electronics. If you don't need the added
    horsepower why heat your PC & house with an over sized supply.
    <>< Rob
     
    Rev.3.20, Dec 19, 2010
    #8
  9. Yousuf Khan

    willbill Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    Sat, 18 Dec 2010 20:18:43 -0800, Ant <> wrote:

    > Thanks. I will be using my box as a workstation, media center (have
    > three TV tuners), and gaming. :)



    Given that, you might want to spend more for a low ripple PSU.

    e.g. I'm currently building 4 new machines, with primary focus on
    using at least a couple of them for high end playback of stereo
    music from flac files.

    Does low ripple make a difference for this?

    I frankly don't know, but have enough suspicion at this point
    that it does, which has lead me to buy higher end (more
    expensive) PSU units that have lower ripple.

    Bill
     
    willbill, Dec 19, 2010
    #9
  10. Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 04:57:04 -0800 (PST), "Rev.3.20" <>
    wrote:
    >Just a side note for others who may be considering a larger supply.
    >For those of you building a box or just needing a supply keep in mind
    >the bigger the supply i.e., the higher the output wattage then
    >typically the more it costs to operate. If all you need is 350 watts
    >of output power (typically plenty for business apps.) and you purchase
    >a 1000+ watt supply then the added capacity is only generating heat
    >and costing you money to cool and operate.
    >
    >Too many times people become wrapped around the axle sort of speak
    >with numbers rather than actual requirements. A general rule of thumb
    >for capacity is full load plus 125% for spikes and sustained
    >operation. The same number is used when fusing AC circuits.Some may
    >feel this is a bit conservative for general supply design but it
    >provides plenty of overhead.
    >
    >Remember heat kills electronics. If you don't need the added
    >horsepower why heat your PC & house with an over sized supply.
    ><>< Rob


    So, you believe that a power supply always puts out its maximum capacity (and
    thus its maximum thermal output) regardless of load?

    That theory is quite full of rubbish...
     
    personaobscura, Dec 19, 2010
    #10
  11. Yousuf Khan

    Ken Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 04:57:04 -0800 (PST), "Rev.3.20"
    <> wrote:

    > Just a side note for others who may be considering a larger supply.
    > For those of you building a box or just needing a supply keep in mind
    > the bigger the supply i.e., the higher the output wattage then
    > typically the more it costs to operate. If all you need is 350 watts
    > of output power (typically plenty for business apps.) and you purchase
    > a 1000+ watt supply then the added capacity is only generating heat
    > and costing you money to cool and operate.


    No. That's wrong.
     
    Ken, Dec 19, 2010
    #11
  12. Yousuf Khan

    Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 09:46:52 -0500, personaobscura
    <> wrote:

    >On Sun, 19 Dec 2010 04:57:04 -0800 (PST), "Rev.3.20" <>
    >wrote:
    >>Just a side note for others who may be considering a larger supply.
    >>For those of you building a box or just needing a supply keep in mind
    >>the bigger the supply i.e., the higher the output wattage then
    >>typically the more it costs to operate. If all you need is 350 watts
    >>of output power (typically plenty for business apps.) and you purchase
    >>a 1000+ watt supply then the added capacity is only generating heat
    >>and costing you money to cool and operate.
    >>
    >>Too many times people become wrapped around the axle sort of speak
    >>with numbers rather than actual requirements. A general rule of thumb
    >>for capacity is full load plus 125% for spikes and sustained
    >>operation. The same number is used when fusing AC circuits.Some may
    >>feel this is a bit conservative for general supply design but it
    >>provides plenty of overhead.
    >>
    >>Remember heat kills electronics. If you don't need the added
    >>horsepower why heat your PC & house with an over sized supply.
    >><>< Rob

    >
    >So, you believe that a power supply always puts out its maximum capacity (and
    >thus its maximum thermal output) regardless of load?


    Even if both supplies are 90% efficient, the difference in heat output of a
    1000W supply over a 350W supply is 185%. Even 65W is a lot of waste heat to
    dissipate. The cost difference is trivial but it still is waste heat and more
    importantly, at least to me, more noise.

    >That theory is quite full of rubbish...


    Not all that much rubbish.
     
    , Dec 19, 2010
    #12
  13. Yousuf Khan

    Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 06:46:57 -0800, Ant <> wrote:

    >On 12/19/2010 4:57 AM PT, Rev.3.20 typed:
    >
    >> Just a side note for others who may be considering a larger supply.
    >> For those of you building a box or just needing a supply keep in mind
    >> the bigger the supply i.e., the higher the output wattage then
    >> typically the more it costs to operate. If all you need is 350 watts
    >> of output power (typically plenty for business apps.) and you purchase
    >> a 1000+ watt supply then the added capacity is only generating heat
    >> and costing you money to cool and operate.
    >>
    >> Too many times people become wrapped around the axle sort of speak
    >> with numbers rather than actual requirements. A general rule of thumb
    >> for capacity is full load plus 125% for spikes and sustained
    >> operation. The same number is used when fusing AC circuits.Some may
    >> feel this is a bit conservative for general supply design but it
    >> provides plenty of overhead.
    >>
    >> Remember heat kills electronics. If you don't need the added
    >> horsepower why heat your PC& house with an over sized supply.
    >> <>< Rob

    >
    >Interesting. Yes, my room always get hot during the heat waves/summer
    >(up to 90F degrees) since I live in a desert area. I didn't know using a
    >more powerful PSU would cause more heat. I thought only when I use my
    >computers intensely (compiling, playing computer games [not Flash],
    >etc.) would cause this.
    >
    >So based on my current primary computer setup
    >(http://zimage.com/~ant/antfarm/about/computers.txt ), I did not need
    >that SeaSonic 600 watts SeaSonic S12 PSU? If so, then how much powers
    >did I really need? Please note that I have tons of hardwares in my
    >primary PCs like four SATA drives, three TV tuner cards, an ATI Radeon
    >4870 HD video card, five fans, Intel Core 2 8200 CPU, etc. I will be
    >using most of the same hardwares for i7 setup. Will I still need that
    >much power?


    Plug the system into a Kill-A-Watt, PowerAngel, or some such, and find out how
    much you're using. Multiply that by 1.3, 1.5, or whatever your "safety
    margin" + PS (in)effiency factor, and there you go.

    >I am replacing the old PSU since I had it since 2006. I don't know how
    >much longer this old PSU will last and don't want to wait for it to die
    >on my upcoming upgraded system. I know some lower watts PSUs (e.g.,
    >Antec, Enlight) do not last that long for me. The last Antec PSU killed
    >my MSI motherboard, AMD Athlon 64 X2 939 CPU, NVIDIA GeForce 8800 GT
    >video card, etc. :(
     
    , Dec 19, 2010
    #13
  14. Yousuf Khan

    willbill Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    Sun, 19 Dec 2010 06:38:17 -0800, Ant <> wrote:

    > What is lower ripple PSU? I assume the Corsair one isn't one?


    Read: 550W Roundup: Three PSUs at Different Prices
    by Martin Kaffei on 10/28/2010
    http://www.anandtech.com/show/3985/three-550w-psus-for-different-prices

    Of the 3 PSU in this review, the Antec TP-550 TruePower New 550W
    has the lowest ripple.

    Bill
     
    willbill, Dec 19, 2010
    #14
  15. Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 11:15:51 -0600, ""
    <> wrote:

    >On Sun, 19 Dec 2010 09:46:52 -0500, personaobscura
    ><> wrote:
    >
    >>On Sun, 19 Dec 2010 04:57:04 -0800 (PST), "Rev.3.20" <>
    >>wrote:
    >>>Just a side note for others who may be considering a larger supply.
    >>>For those of you building a box or just needing a supply keep in mind
    >>>the bigger the supply i.e., the higher the output wattage then
    >>>typically the more it costs to operate. If all you need is 350 watts
    >>>of output power (typically plenty for business apps.) and you purchase
    >>>a 1000+ watt supply then the added capacity is only generating heat
    >>>and costing you money to cool and operate.
    >>>
    >>>Too many times people become wrapped around the axle sort of speak
    >>>with numbers rather than actual requirements. A general rule of thumb
    >>>for capacity is full load plus 125% for spikes and sustained
    >>>operation. The same number is used when fusing AC circuits.Some may
    >>>feel this is a bit conservative for general supply design but it
    >>>provides plenty of overhead.
    >>>
    >>>Remember heat kills electronics. If you don't need the added
    >>>horsepower why heat your PC & house with an over sized supply.
    >>><>< Rob

    >>
    >>So, you believe that a power supply always puts out its maximum capacity (and
    >>thus its maximum thermal output) regardless of load?

    >
    >Even if both supplies are 90% efficient, the difference in heat output of a
    >1000W supply over a 350W supply is 185%. Even 65W is a lot of waste heat to
    >dissipate. The cost difference is trivial but it still is waste heat and more
    >importantly, at least to me, more noise.


    Wait. What?

    Using your 90% efficiency for both examples, a 1000 watt supply driving a 350
    watt load would be "wasting" only 35 watts. Guess how many watts a 350 watt
    supply driving the exact same load would "waste".

    Bonus question: Now guess which supply is likely to be generating more
    electrical distortion on its outputs.

    Double Bonus question: Guess which supply is likely to drive the owner to
    distraction from its internal fan noise?

    >>That theory is quite full of rubbish...

    >
    >Not all that much rubbish.


    At least as much as your analysis ;-)
     
    personaobscura, Dec 20, 2010
    #15
  16. Yousuf Khan

    Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Sun, 19 Dec 2010 19:50:51 -0500, personaobscura
    <> wrote:

    >On Sun, 19 Dec 2010 11:15:51 -0600, ""
    ><> wrote:
    >
    >>On Sun, 19 Dec 2010 09:46:52 -0500, personaobscura
    >><> wrote:
    >>
    >>>On Sun, 19 Dec 2010 04:57:04 -0800 (PST), "Rev.3.20" <>
    >>>wrote:
    >>>>Just a side note for others who may be considering a larger supply.
    >>>>For those of you building a box or just needing a supply keep in mind
    >>>>the bigger the supply i.e., the higher the output wattage then
    >>>>typically the more it costs to operate. If all you need is 350 watts
    >>>>of output power (typically plenty for business apps.) and you purchase
    >>>>a 1000+ watt supply then the added capacity is only generating heat
    >>>>and costing you money to cool and operate.
    >>>>
    >>>>Too many times people become wrapped around the axle sort of speak
    >>>>with numbers rather than actual requirements. A general rule of thumb
    >>>>for capacity is full load plus 125% for spikes and sustained
    >>>>operation. The same number is used when fusing AC circuits.Some may
    >>>>feel this is a bit conservative for general supply design but it
    >>>>provides plenty of overhead.
    >>>>
    >>>>Remember heat kills electronics. If you don't need the added
    >>>>horsepower why heat your PC & house with an over sized supply.
    >>>><>< Rob
    >>>
    >>>So, you believe that a power supply always puts out its maximum capacity (and
    >>>thus its maximum thermal output) regardless of load?

    >>
    >>Even if both supplies are 90% efficient, the difference in heat output of a
    >>1000W supply over a 350W supply is 185%. Even 65W is a lot of waste heat to
    >>dissipate. The cost difference is trivial but it still is waste heat and more
    >>importantly, at least to me, more noise.

    >
    >Wait. What?
    >
    >Using your 90% efficiency for both examples, a 1000 watt supply driving a 350
    >watt load would be "wasting" only 35 watts. Guess how many watts a 350 watt
    >supply driving the exact same load would "waste".


    True. <crap> ...except that a 1kW power supply may be a lot less efficient
    at 1/3 of its rating.

    >Bonus question: Now guess which supply is likely to be generating more
    >electrical distortion on its outputs.


    Electrical "distortion" on DC outputs? Properly designed, neither. IOW, not
    enough information.

    >Double Bonus question: Guess which supply is likely to drive the owner to
    >distraction from its internal fan noise?


    I thought I mentioned that.

    >>>That theory is quite full of rubbish...

    >>
    >>Not all that much rubbish.

    >
    >At least as much as your analysis ;-)


    Nope, not all that much.
     
    , Dec 20, 2010
    #16
  17. Yousuf Khan

    willbill Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    Sun, 19 Dec 2010 06:38:17 -0800, Ant <> wrote:

    > What is lower ripple PSU? I assume the Corsair one isn't one?


    Assuming you mean the Corsair AX750 that I gave a ref to,
    it has low ripple (see the conclusion comments).

    It is also a 80+ gold PSU, which means that at 10% usage
    to 20% usage, which is where you'll be most of the time,
    it is 82-to-88% efficient.

    Also see:

    http://en.wikipedia.org/wiki/Power_supply_unit_(computer)

    and

    http://en.wikipedia.org/wiki/80_PLUS

    Bill
     
    willbill, Dec 20, 2010
    #17
  18. Yousuf Khan

    Rev.3.20 Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLIReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    On Dec 20, 4:24 am, willbill <> wrote:
    > Sun, 19 Dec 2010 06:38:17 -0800, Ant <> wrote:
    >
    > > What is lower ripple PSU? I assume the Corsair one isn't one?

    >
    > Assuming you mean the Corsair AX750 that I gave a ref to,
    > it has low ripple (see the conclusion comments).
    >
    > It is also a 80+ gold PSU, which means that at 10% usage
    > to 20% usage, which is where you'll be most of the time,
    > it is 82-to-88% efficient.
    >
    > Also see:
    >
    > http://en.wikipedia.org/wiki/Power_supply_unit_(computer)
    >
    > and
    >
    > http://en.wikipedia.org/wiki/80_PLUS
    >
    > Bill


    OK, assuming efficiency and size has been established here's another
    consideration concerning the earlier ripple mention.

    Another side note that may be worth mentioning for Audio Video
    applications is grounding. Provided you have a good ground your
    usually OK but if not that's where your ripple factor will really be
    noticeable. Older homes may not have ground receptacles (or have
    ungrounded ground receptacles) which can allow AC hum and be very
    apparent when working with audio. Typically cheaper designed power
    supplies tend to have the noisiest outputs because of minimal
    filtering. The fewer / least expensive components a manufacturer can
    use the wider the profit margin is for them. A manufacturer can
    produce a supply with what appears to be a great power output
    specification but be the output voltages may not be very clean
    resulting in AC Hum, easily heard in audio.

    This is true of any audio design. Ever turn up an audio amp with no
    input and listen to your speakers? The better designed filtering a
    system has, the less hum you will hear. The same example can be heard
    with TV audio. The noise is both audible and measurable. in any power
    supply / amplifier circuit.

    Granted most homes are grounded now days but older ones may not be.
    One trick that can help this if running multiple PCs is to ground them
    to each other.so that they have the same ground potential. Ideally
    this isn't necessary but can help if needed.
     
    Rev.3.20, Dec 20, 2010
    #18
  19. Yousuf Khan

    DevilsPGD Guest

    Re: Good PSU choice? CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI ReadyCrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 PowerSupply?

    In message <> personaobscura
    <> was claimed to have wrote:

    >Using your 90% efficiency for both examples, a 1000 watt supply driving a 350
    >watt load would be "wasting" only 35 watts. Guess how many watts a 350 watt
    >supply driving the exact same load would "waste".


    Keep in mind that a PSU designed to be 90% efficient delivering 1000w
    will likely not be 90% efficient delivering 350watts.

    It certainly won't be wasting 10% of it's maximum capacity at all times,
    but most PSUs aren't as efficient when running outside their designed
    output ranges.

    http://www.overclock3d.net/reviews/power_supply/corsair_hx650w_650w_atx_psu/4
    is one such example, where efficiency ranges from 75%-88% dependant on
    load.
     
    DevilsPGD, Dec 20, 2010
    #19
  20. Yousuf Khan

    Yousuf Khan Guest

    On 19/12/2010 8:40 PM, zzzzzzzz wrote:
    > On Sun, 19 Dec 2010 19:50:51 -0500, personaobscura
    > <> wrote:
    >
    >> On Sun, 19 Dec 2010 11:15:51 -0600, ""
    >> <> wrote:
    >>
    >>> On Sun, 19 Dec 2010 09:46:52 -0500, personaobscura
    >>> <> wrote:
    >>>> So, you believe that a power supply always puts out its maximum capacity (and
    >>>> thus its maximum thermal output) regardless of load?
    >>>
    >>> Even if both supplies are 90% efficient, the difference in heat output of a
    >>> 1000W supply over a 350W supply is 185%. Even 65W is a lot of waste heat to
    >>> dissipate. The cost difference is trivial but it still is waste heat and more
    >>> importantly, at least to me, more noise.

    >>
    >> Wait. What?
    >>
    >> Using your 90% efficiency for both examples, a 1000 watt supply driving a 350
    >> watt load would be "wasting" only 35 watts. Guess how many watts a 350 watt
    >> supply driving the exact same load would "waste".

    >
    > True.<crap> ...except that a 1kW power supply may be a lot less efficient
    > at 1/3 of its rating.


    The 80-Plus rating is a type of guarantee of 80%+ efficiency at several
    load levels, from 20% on upto 100%. There will be a level at which any
    power supply will be most efficient somewhere between that (perhaps
    it'll be 90% efficient at that level), but it should remain at or above
    80% efficiency all throughout its range.

    Yousuf Khan
     
    Yousuf Khan, Dec 20, 2010
    #20
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