Will An 850W PSU Be Enough?

thesnowdog1971 · 21 Aug 2023 at 18:36

Hi

So I'm planning a new build for a new VR PC, but I'm having trouble deciding on which PSU to get. :confused:

It's going to have a 7800X3D CPU, 64GB of DDR5 and a 7900XT. I'm also going to have 2 x 4TB SATA hard drives, 1 x 120GB SATA and 1 x 500GB SSDs and a 1Tb M2 drive.

Would an 850W PSU do the job? Or will it be safer for me to spend a bit more and go for a 1000W PSU instead?

I'm pretty sure I remember reading somewhere that AMD recommend an 850W PSU, and the 7800X3D is crazy efficient, so I'm thinking that I might be okay going for the 850W option.

thesnowdog1971 · 21 Aug 2023 at 20:04

Tetras said:
Are you buying a 2x 8 pin or a 3x 8 pin 7900 XT (e.g. Nitro)?

Minimum 750 on the spec page.

No idea which one I'm going to get. One of the cheaper ones lol

Probably something like a Sapphire Pulse I would have thought.

thesnowdog1971 · 22 Aug 2023 at 00:34

Tetras said:
If you have 2x 8 pin it's a lot easier to find that 3x 8 pin. A lot of ATX 3.0 PSUs don't have enough ports for 3x 8 pin and 2x EPS12v.

If your case is compatible, maybe go with the Corsair SHIFT, since it seems competitively priced right now?

An alternative if you need 3x 8 pin is to get an older pre-ATX 3.0/PCIE5 PSU like the Strix.

My basket at OcUK:

1 x Corsair RM850x Shift ATX 3.0 80 Plus Gold Power Supply (CP-9020252-UK) (SKU: CA-279-CS) = £134.99

1 x ASUS ROG STRIX 1000W 80 Plus Gold Modular Power Supply (SKU: CA-05N-AS) = £179.99

Total: £322.97 (includes delivery: £7.99)

Thanks, decided to go for the 850W one.

Ta!

thesnowdog1971 · 28 Aug 2023 at 18:19

pastymuncher said:
It's a bit late now but does your case have room for the cables on the Corsair RM850x Shift? It's cables do not attach to the normal place on the psu but on the side instead.

Not late at all, I won't be getting the parts until November.

I'm just planning ahead.

I'm now toying with the idea of getting a 7900XTX card in April or May next year instead of a 7900XT.

The case that I'm planning on getting, assuming that it releases here in the UK by then, is a Montech 903 Air MAX.

thesnowdog1971 · 10 Sep 2023 at 10:02

pastymuncher said:
Great value cases. I don't think the Corsair RM850x Shift will fit as there doesn't seem to be enough space between the psu and side panel for the connectors let alone the cables. Best to go with a more conventional design psu.

Yup, thanks. I think I might go for that 1000W one anyway, now that I'm thinking about it, because there's always the chance that I'll go for a 7900XTX instead of a 7900XT. So if I go for the 1000W PSU I'll be keeping my options open next year.

Thanks for your help!