PSU enough for 470SLI OC'd in my system?

Discussion in 'Videocards - NVIDIA GeForce' started by h220wnzj00, Aug 18, 2010.

  1. h220wnzj00

    h220wnzj00 Member Guru

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    GPU:
    Sapphire 7970 Dual-X
    Hey guys,

    I know with OC this is going to be pushing it... Just based on what I have so far, would I be able to add another 470 to SLI and still be good with my TPN-750?
     
  2. Peter Buxu

    Peter Buxu Master Guru

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    GPU:
    BFG GeForce GTX 280 OCX
    quote from Hilbert Hagedoorn:

    "GeForce GTX 470 in SLI

    A second card requires you to add another ~200 Watts. You need a 700 Watt power supply unit.
    "

    You should be good but you would be stressing your PSU a lot with your components
     
  3. AnthraxPants

    AnthraxPants Banned

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    XFX 4890HD 1GB
    I'm looking for your PSU's specifications currently, could you post your 12V rails Amp ratings and perhaps what your BIOS is currently showing your systems 12V to be, while I find your PSU's specs.
    If your PSU has at least two 12V rails which each supply enough Amps for a GTX470 while still maintaining 12V without significant V Droop (the figure for 12V in your BIOS does not drop too much below 12, 11.9 for example may be adequate but too much below that and your graphics card won't get enough power. A very good quality PSU should display something like 12V, 12.1V or maybe 12.2 in your BIOS depending on the accuracy of what your motherboard's BIOS displays (you may what to use a third party app to double check your system voltages).

    If your BIOS shows 12V to currently be a solid 12V with your current setup then it may be able to handle a second card, but you should wait for confirmation that the Antec TPN-750 Blue can handle two GTX470 from someone else with the same PSU. I'd imagine you'd be pushing it, but could possibly scrape in if the PSU can deliver 12V with enough Amps for two GTX470. You would need to post your PSU specifications though to get an accurate answer.

    Here is a link to the Antec PSU Calculator
    http://www.antec.outervision.com/

    I found your PSU specs I think here
    http://www.antec.com/Believe_it/product.php?id=MTc2MQ==

    Does the GTX470 need a 6 pin and an 8 pin connector, if so then your PSU should just be capable of running a second GTX470 I imagine? Still, confirmation from someone already running such a setup would be advisable. Your PSU can supply 750W but won't give much room for overclocking, though overclocking two GTX470 in SLI is a little bit insane anyway and probably quite loud and hot.

    I was thinking partly GTX480 SLI power consumption as opposed to a system with GTX470 SLI. 2xGTX470 should be alright.
     
    Last edited: Aug 18, 2010
  4. kkaddu

    kkaddu Member

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    GPU:
    MSI 580 lightning
    Well after that last post i feel cornered into having to upgrade PSU

    i have Antec NeoPower 650W (3 rails @19A)
    and want to get two GTX 470s for SLI since the price is right (@$290)
    is it possible to run this set up without needing new power supply?
    I do not plan to overclock anything really
     

  5. Vood007

    Vood007 Master Guru

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    GPU:
    Too
    Id say its not enough. With no OC on CPU and GPU yes, but alone a CPU oc´d to over 4GHz draws much more power compared to stock clocks.

    From http://www.anandtech.com/show/2404/5 - Its about QX9650 but should not make a big difference with i7:

    [​IMG]

    The step from 3.2GHz to 4GHz is already +100W. Plus around 500W for two OC´d 470s...
     
  6. hitsugy

    hitsugy Member

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    GPU:
    eVGA GTX 470
    A good 700W PSU is enough...
     
  7. eternitykh

    eternitykh Master Guru

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    GPU:
    EVGA GTX 670 FTW+ 4GB SLI
    to OP's system:

    with an overclocked i7 and SLi overclocked 470s. no 750 isn't enough. not even close, you'll probably get random crashes or poor performance, or even burn out your PSU down the line.

    you'll be needing a 1kw PSU, if you plan to run a system like that without stressing a PSU. remember, idealy, you NEVER want to run your PSU at 100% load in the first place

    750w would be for a OC'd system with SINGLE OC'd 470/480 with a bit of headroom for not stressing your PSU and efficiency. add another 250w to that for a second card, there you have it, 1kw.

    where am i getting these calculations? think about it. your CPU is probably eating 200~250w alone (being OC'd), 2x OC'd 470s would be more like stock 480s, so that's at least 250+ each. so... 750 for CPU and GPUs ....... that's not including any storage, motherboard, ram, fans, and any other components you might have. hope that made sense.

    to kkaddu's system, with absolutely NOTHING OC'd 650w is "enough", though it's cutting it quite close. but if you have a quality PSU that you trust, go for it. you mentioned 3x rails on your 12v. make sure you have enough amps to be distributed. or else that would be a no go. another reason why i prefer single rail designs (no, not trying to have an argument about that haha, just a preference.)

    19amps each should be good for each 470. i hope 2 of those 3 rails are dedicated to the PCI-E power connectors.
     
    Last edited: Sep 15, 2010
  8. Wanny

    Wanny Guest

    I'm running all my OCs on HX850 and I don't feel like it's struggling at all...

    I might be near to load it in a few occasions tho, I don't know.
     
  9. eternitykh

    eternitykh Master Guru

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    GPU:
    EVGA GTX 670 FTW+ 4GB SLI
    yeah haha, i almost forgot about your system, probably cutting it real close too, unless my calculations are off.... or that just proves the quality of corsair PSU's haha.

    let's see, if i take back 50w from cpu (200 instead of 250) and exactly 250 on each 470, that's still 700w from just cpu + gpu. + other miscellaneous (storage, fans, usb's and what not) say... 100w? that's 800w at full load, 800/850 = about 95% load on the PSU, that's cutting it REEAAALL close..... not enough headroom for my liking.
     
  10. WacKEDmaN

    WacKEDmaN Guest

    Last edited by a moderator: Sep 16, 2010

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