Corsair HX 650W PSU: Enough Punch for Nvidia GTX 1080?

• 

  [Deactivated] on 05/03/2017 - 15:01

  +1

  Should be okay
  AS little on the low size, but I would NOT use anything less than 650w with that config

  • 

    dealhunt on 05/03/2017 - 15:07

    Thank you.
    I know the power is "just" enough but before going on I want to see what other people with a similar configuration have to say.

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  airal3rt on 05/03/2017 - 15:20

  I have the same PSU, Corsair make good PSUs so you'll be fine with 650w. GPUs have gotten more power efficient over time also so you're unlikely to run into problems like a few years ago.

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  elusive on 05/03/2017 - 15:27

  +5

  It's far more than enough.

  Peak power draw of the card is a tad over its TDP of 180W: http://www.guru3d.com/articles-pages/nvidia-geforce-gtx-1080…

  Factor in around 100W for the CPU (yours is actually TDP 65W), add another 100W margin for drives and motherboard (again, overkill), and you only really need around 400W strictly speaking.

  But if you want hard numbers? They got around 335W wall power consumption while running Crysis 3 here: http://www.anandtech.com/show/10325/the-nvidia-geforce-gtx-1…

  I just ran a Furmark GPU stress test + 7/8-core CPU burn (i7-7700k, 95W TDP) and got around 300-340W reported by my UPS. Running an AX860i (was planning to do dual-GPU on it). Actually, I think my monitor is on the UPS too, so actual system power consumption is maybe 50W lower.

  A true 400W PSU is enough. 500W if you really want to be safe. Just make sure the PSU can actually provide its rated power; the HX650 does: http://www.hardwaresecrets.com/corsair-hx650-gold-power-supp…

  I think most of the massive PSU overspeccing is from old/cheap power supplies where a good chunk of the rated power was actually supplied on the 5V rail, where we need most of it on 12V now. Your HX650, for example, can provide a full 648W on the 12V rail. The other factor was GPUs from ~4 years ago that drew 300W+, but the GTX 1080 uses half that power.

  • 

    elusive on 05/03/2017 - 15:38

    +1

    Just another data point, Corsair Link reports ~350W power in, ~320W power out.

  • 

    dealhunt on 05/03/2017 - 17:29

    Thanks for the detailed and massive information.

    I also read another review from Guru3D where they say that on an average system a 650W PSU would suffice even so I understand that is just enough: [Guru3D] (http://www.guru3d.com/articles-pages/nvidia-geforce-gtx-1080…)

    And I've one more question for you, I don't remember how many 12V cables (or rails) the PSU has so that means my PSU can output 648W on all cables together or the output is diverted only on some main cables?

    • 

      elusive on 05/03/2017 - 18:29

      +1

      The HX850 has a single 12V rail, I believe. But you shouldn't carry more than a certain amount of current on each cable, depending on cable thickness (gauge).

      The GTX 1080 only has a single 8-pin PCIe power socket, so it doesn't really matter. Just plug it in.

      For GPUs that have more than one socket, or for dual-GPU, generally you don't want to use two plugs on the same cable unless the cable is thick enough. IIRC it's something like 16AWG or 18AWG (where lower AWG is thicker).

      • 

        dealhunt on 05/03/2017 - 18:32

        Do you mean the HX650 right?

      • 

        elusive on 05/03/2017 - 18:54

        @dealhunt: Sorry, yes, HX650.

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  Diji1 on 05/03/2017 - 15:34

  Why did you decide to get a i5 K CPU + Z series chipset instead of non K i5 + H/B series chipset?

  This frees up money for more powerful video card and/or monitor.

  Ignore this if this system isn't being built for gaming.

  • 

    dealhunt on 05/03/2017 - 17:36

    Good question and thanks for asking.

    I started looking for an average and affordable gaming machine so I decided for the i5 6500, the H170 and maybe an R480 or a 1060 since I most probably won't overclock.
    Then Intel and nVidia realized that they no more hold the monopoly and started dropping the prices so now I'm looking for another solution based on the current and near future prices drop.

• 

  ChillBro on 05/03/2017 - 17:34

  +1

  As above, 650W is plenty. Even Nvidia only recommends 500W on their site - https://www.nvidia.com/en-us/geforce/products/10series/gefor…

  Graphics cards seem to be getting more and more efficient nowadays to the point where even laptops can have a full GTX 1070/1080 onboard and not a gimped one.