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3WAY SLI GTX 770 Wattage req

Discussion in 'General Hardware' started by MaximusE, Aug 7, 2014.

  1. MaximusE

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    Hey guys,

    I currently run a 3way gtx 770 setup with an 4930k and a corsair ax860i.

    i want to get a western digital black for storage but i think the psu is not enough for the system?

    cheers
     
  2. Ferrum Master

    Ferrum Master

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    OCed or not?
     
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  3. MaximusE

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    at the moment everything runs default
     
  4. Jetster

    Jetster

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    64K says thanks.
  5. newtekie1

    newtekie1 Semi-Retired Folder

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    Hard Drives use like 10w, 15w max, if you think you are that close to the limit of your PSU you shouldn't be running the system at all.
     
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  6. 64K

    64K

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    Jetster offered a good idea. Get a watt meter and measure your system draw to see how close you are.
    If not then take a look at this for watts used per card

    Peak: Crysis 2 at 1920x1200, Extreme profile, representing a typical gaming power draw. Highest single reading during the test.

    [​IMG]

    http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_770/25.html

    Your 3 GTX 770s shouldn't need more that 540 watts. That leaves 320 watts for the rest of your system which is fine. Your PSU provides +12V@71.6 amps for 859.2 watts so you should be fine on total system draw with the PSU you have. If you start looking at overclocking then upgrade to a 1050 watt Seasonic or Corsair PSU.
     
  7. Ferrum Master

    Ferrum Master

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    Well that PSU has also a reserve and is actually higher...

    The only thing is system power up... especially with bunch of spinners that consume a really high spike of current. I mean the current overprotection may kick if otherwise.

    I vouch it is sufficient enough, but I'd sell it, and bought a 1000W just for peace in soul... coz three card setup is really CPU greedy and you will need to push the cpu to skies.
     
    Last edited: Aug 7, 2014
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  8. MaximusE

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    thanks for all the answers

    the thing is when i try to run a game or a benchmark with both 3 cards i get kind of a signal loss..the screen is starting to shaking and then i get a black screen but the sound at the back keeps going until u press control alt delete and then it restarts itself

    i tried benchmarking with one card at the moment and everything looks ok
     
  9. Jstn7477

    Jstn7477

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    Sounds like you might have an overload there/tripping the over-current protection. Have you tried benching with just two cards only?
     
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  10. MaximusE

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    am on that at the moment.

    i just used the current psu calculator http://www.extreme.outervision.com/PSUEngine

    included the sound card which am not using yet including the hard drive for storage and it suggests the following:


    Minimum PSU Wattage:807 W
    Recommended
    PSU Wattage:
    *[​IMG][​IMG][​IMG][​IMG]
     
  11. MxPhenom 216

    MxPhenom 216 Corsair Fanboy

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    So wattage is one thing, but amps is another. Nvidia recommends a minimum of 42A (amps) on the 12v rail for a SINGLE card. I would have opted for a 1000w PSU if I were going to run 3 top tier GPUs like the 770s.
     
  12. Jstn7477

    Jstn7477

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    12V*42A = 504W then for a full system with a single GTX 770 installed. Therefore, yes, a 1000w or greater PSU should be good as that would allow 250W for each additional card assuming the PSU drives the minor rails (3.3/5V) from the 12V source (and actually delivers 1000W of 12VDC power to begin with).
     
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  13. cadaveca

    cadaveca My name is Dave

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    PCIe slots use 12V and 3.3V. So if 3.3V is under high load...and you have HDDs spinning up at the same time...

    12V isn't the only consideration in multi-GPU systems. Overlooking 3.3V is why many "OK" PSUs, that should provide sufficient wattage, fail in actual use. Each slot should pull about 3-5A @ 3.3 line, depending on stock/OC, etc.

    I see many suggest 75W for PCIe slot (not speaking about anyone here), but most posting this don't realize that that 75W figure is both 12V and 3.3V, combined.
     
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  14. Champ

    Champ

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    Sounds like an issue I had with my home theather. Could be overloading the video cables if they are the cheap type. Just a shot in the dark. Brought better ones and it stopped my htpc from doing the same.
     
  15. 64K

    64K

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    Thanks. I did not know that about the 3.3V.

    Yeah, OP if you're having problems with your PSU even if the PSU calculator says it's enough then it's a very good idea to upgrade your PSU and pull one GTX 770 out until you do. Take Dave's advice and cover the 3.3V requirement in your next PSU choice and go with a minimum 1050 watt Seasonic or Corsair and maybe consider a 1200 watt if you think you might OC.
     

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