PSU Wattage for dual GPU setup

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Hello there. What kind of PSU do you use to power your dual GPU setups? I’m doing Ryzen 1700 build and I can’t decide between 850W and 1000W PSUs. On one hand, 1000W seems like an overkill, on the other hand, I fear that 850W might somehow limit future upgradeability of the system.

So for now I have Ryzen 1700, X370 Taichi, factory overclocked RX580, binned and overclockable 1070ti, 32 GB RAM and some drives - SATA SSD, good old fashioned blu ray and HDD. I have yet to buy PSU and CPU cooler. As far as CPU cooler goes, I’d probably go with some generic 280mm AIO and switch included fans to better ones.

Future upgrades might include more SSDs, more RAM, maybe a pcie card and maybe a switch from 1070ti to Vega. I will try to overclock a CPU.

I’d prefer more quiet over more energy efficient – this is another reason why I’m kind of drawn to 1000W PSUs.

This is going to be personal/workstation PC. I would love to get Qubes with Windows HVM and GPU passthrough going but since I have a Nvidia card, I don’t this is going to be possible. So I will most likely use KVM.

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An 850w should work fine with two cards, but a 1000w would theoretically be quieter because it’s not being taxed as much.

Either way, make sure to get a decent power supply and not some Shenzhen Special. When power supplies go pop they can take other things with them.

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I’d say even a 850w would be plenty, but if you do go 1000w, try and get a platinum level 80+ bronze, for long term money saving, when cards are using less power

[Edit… what @w.meri said]

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Thanks for answers. Yeah, my first was choice was actually platinum level Corsair HX850 . But when I’ve become intrigued by Seasonic Prime Titanium series since it has insanely good reviews. Though of course it’s more expensive even when taking slightly higher efficiency level into account.

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Put your specs into SeaSonics PSU Calc and it says 700W is enough.
They recommend the Prime Focus 850W

On the subject of efficency: It does not matter. 80% vs 90% at 700W is only 70W difference. At 24 hours full load that is 1.7kW. In my case, that would be 38 cent per day difference (at full load, that is).

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OP is looking for silence though, so a bigger, beefier PSU might be better for them because (in theory) the increased efficiency would make it run cooler and thus quieter.

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SeaSonic claims the Prime Platinum line only turns the fan on at 40%ish load. With the rig at idle, we are looking at 60 to 90W.
Full load would be 700W-ish
With the 1200W unit, the fan would be just out of the Hysterisis phase of the fan curve.

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If you’re considering a 1080 Ti at all for one of the GPUs, 1000W will be the sweet spot, and no less than 80+ Platinum.

1000W Gold is good enough for a RX 580 and a 1070 Ti. 850W might be pushing it for the fan curve of the PSU so 1000 Gold is good. EVGA has a good option:

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I used the gold 1000w EVGA G2 in my first build, it’s around 5 years old & has never missed a beat.

My next 2 I’ve used the EVGA P2 1200w, they are dead silent, the G2 still makes a bit of noise- not sure if the G3 change this though.

My main rig now runs an overclocked 1700, 2 overclocked 980 tis, a big watercooling setup & a heap of lighting/controllers/drives.

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Just to have said it: The efficency and the output wattage have nothing to do with one another.
However having more efficency (Bronze, Silver, etc.) means less heat in providing the power.

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I have a pair of RX Vega 64s with a 2700X on an HX850i

Yes it is borderline, and the GPUs are never run on anything higher than balanced.

But it works and the PSU fan rarely activates.

If you aren’t running anything that hungry, an 850 will be FINE.

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