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PSU How many watts does your rig draw?

Discussion in 'Hardware' started by Parge, 10 Jan 2015.

  1. Parge

    Parge the worst Super Moderator

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    I picked up one of these power draw meters from Amazon a while ago. I've been using it to measure how much my AM1 NAS/HTPC is sucking up (20W btw).

    However, last week I started measuring my main rigs power draw in various scenarios. My specs are below by the way, and both the GPU and CPU are overclocked.

    At idle I draw 80W. During gaming around 250W, and at max load (prime 95 and furmark running at the same time), 320W.

    I hope that puts into perspective the size of PSU people should be looking at for modern, single card rigs. Everyone likes to talk about 'headroom' but even with a lowly 450W PSU, I've still got 130W of power left in the tank, and that doesn't take into account the fact that most good quality PSUs will actually output a decent amount more than their stated figure.

    Does anyone else measure their rigs power draw?
     
  2. meandmymouth

    meandmymouth Well-Known Member

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    I would like to but have never got round to buying a power draw meter. Maybe next month. It would be interesting to see what it's drawing.
     
  3. GeorgeStorm

    GeorgeStorm Aggressive PC Builder

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    Yeah most people have PSUs capable of providing far more power than needed, I've got a similar device myself and whilst I haven't used it in a while from memory I was using less than I had imagined.
     
  4. CrapBag

    CrapBag Well-Known Member

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    My pc is very similar to Parges in spec although I run stock clocks on my cpu and 970 but I have an 880w psu, complete overkill but there's no point in me buying another one right now. From the days of running SLI when I thought I'd need the extra power.

    I would like to know what my pc is pulling though.
     
  5. meandmymouth

    meandmymouth Well-Known Member

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    I'm running an overclocked 3570K and two 660's but I doubt that might 850W PSU is being taxed that much.
     
  6. rollo

    rollo Well-Known Member

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    Unless your running AMD gpus or using 3+ nvidia cards a 800 watt psu is overkill.
     
  7. sandys

    sandys Well-Known Member

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    I pull 1.2kw on a 90+ PSU ..... mwha ha ha ha ha :rock:

    Keeps the room warm this time of year.
     
  8. Madness_3d

    Madness_3d Bit-Tech/Asus OC Winner

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    About 850W with my monitor, which given I have an 850W PSU sounds fine to me. Does make the point of how shamefully inefficient my desktop is... Will be building a new one some time next year :D
     
  9. Isitari

    Isitari Active Member

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    Be careful about buying a PSU that gives you only a little headroom though (but yeah 800W are generally overkill). The main factor to take into account in the long term is capacitor ageing which I think is approximately 10% loss of power per year (depending on usage I'd imagine). One more thing to take into account though is that a PSU will generally give better efficiency when it's under a middling load.
     
  10. IvanIvanovich

    IvanIvanovich будет глотать вашу душу.

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    My sig rig... about 65-75w on idle/light load, 320w on full load. I keep trying to tell people, they don't need those 700w and above PSU unless they are going to be using an MP motherboard and like 3x SLI... but still most people won't listen. A lot has changed in the last 10 years, and those mega PSU are simply unnecessary with how efficient modern components are.
     
  11. wolfticket

    wolfticket Downwind from the bloodhounds

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    It's the "how massively over-specced is your PSU?" thread :)

    I actually have one of those things but haven't used it on my PC for a while. I'll check next time I have the opportunity.

    I'm more looking forward to using it on the AM1 based system I'm building though :)
     
  12. Deders

    Deders Well-Known Member

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    I'm running mine pretty close to the mark, my power meter reads 116W idle, modern games run it between 430 and 450, I have seen it go as high as 480 in Crysis 3 (Welcome to the Jungle) but if you take 92% efficiency into account then those figures are:

    Idle: 107W
    Gaming: 396-414W
    Crysis 3: 442W

    These are at the clocks below. I think it's safe to say I won't modding my GPU's bios any time soon.

    If I switch the meter over to see the max it has seen since I last checked it says 505W which translates to 465W. My 12V rail is apparently good for 450W.

    When I bought the PSU I had a 560TI, which I then upgraded to a 670. I got the 780 because it gave me the proportionally the same performance increase as the increase in pixels from 1680x1050 to 2560x1080 (just over 50%).

    I knew it would be cutting it close but I'm confident it will do me until I upgrade my mobo/psu which will hopefully be less demanding than my trusty i5/MSI combo.

    I never hear the PSU fan spin up but then I don't think I'm supposed to.

    Edit: Just upgraded to the Corsair HX850i. A bit overpowered for now but it will handle a SLI setup if my next monitor upgrade requires it and should see me good for at least the next 7 years, that's just the warranty.
     
    Last edited: 16 Feb 2015
  13. Pete J

    Pete J Employed scum

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    Idle: ~190W
    Gaming (assumed from benchmarking): ~1kW

    :worried:
     
  14. GeorgeK

    GeorgeK Swinging the banhammer Super Moderator

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    For my rig (i7-4770K @ 4.5GHz and SLI 780s) it registers the following

    Idle - 100W
    100% CPU only (just Prime95) - 230W
    100% GPU only (just Furmark) - 670W
    100% CPU and 100% GPU (Prime 95 and Furmark) - 760W

    So when gaming I presume it must draw about 700W (based on both cards running pretty hard but the CPU not so much). Now I know that the last one is a worst case scenario but it makes me glad I have a 1kW PSU - I probably could get away with a 800W PSU but personally I'd rather have a PSU running at about 75% than 95%.
     
  15. Kronos

    Kronos Well-Known Member

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    I got one of these from Shirty when I was considering SLI'ing my GTX 670's. After installing the second card and if memory serves it never posted much above the middle 400's

    I may plug it back in and throw a bit of COD Advanced Warfare around and see what I get.
     
  16. The_Crapman

    The_Crapman Don't phone it's just for fun.

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    I think it's time to amend correct my sig again. :hehe:
    I used to pull about 415W with a 480 which has now been replaced with a 970, but I've also added 2 custom loops, so probably about the same.
     
  17. Shirty

    Shirty W*nker! Super Moderator

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    I concur with the general feelings above, I never saw my rig draw more than 320W, and I expect that's dropped further still since I moved to a 980 and went 100% solid state.

    Having a really awesome 460W PSU was far more important to me than a fairly awesome 750W or an average 1KW unit :)
     
  18. Corky42

    Corky42 Where's walle?

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    While i agree most systems don't need a high wattage PSU it's worth taking into account that IIRC most PSU are most efficient at around 40-60% load, and what you read as power draw at the wall maybe around 10-15% higher than your system actually draws due to some power being lost converting AC to DC.
     
  19. LennyRhys

    LennyRhys Oink!

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    You may remember the test I did 2 years ago with GTX480 SLI, and it was interesting to see just how misled people can be by what they read in reviews. Gaming, which is the most intense use my SLI setup ever saw, didn't bring the system to 600W at the wall... in fact it was barely above 550W, and that was with the CPU overclocked.

    I suspect my current system with Xeon and 970 will be respectable, but I'll have to test it (at stock and overclocked).
     
  20. wolfticket

    wolfticket Downwind from the bloodhounds

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    While it is true the PSUs tend to be most efficient around 50% load, with most decent modern PSUs are actually fairly uniform across different loads.

    To take a common example: http://www.plugloadsolutions.com/psu_reports/CORSAIR_CMPSU-500CXV2_ECOS 2415_500W_Report.pdf (PDF)

    And the drop off works both ways.
    I've been looking at how efficient PSUs tend to be at very low loads (<20%) for a new AM1 build and the numbers aren't particularly encouraging. Commonly well under 80%.

    Indeed the 80+ spec is that it is 80%+ efficient across loads above 20% draw.
    If you have your computer idling (or office-ing :)) a for longer periods than you spend doing intensive things it seems to me you might lose more efficiency at the bottom than you gain at the top with a powerful PSU.
     
    Last edited: 11 Jan 2015

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