PSU Size recomendation

Djwayne · 17 Dec 2021 at 12:08

Can someone give me a sugggestion as to what size PSU would be required to run an RTX 3090 FE with an i9 12900k based system? I Havent built a machine in ages and have to say am a bit out of touch with the current power requirements so looking for soime advice.

BUDFORCE · 17 Dec 2021 at 12:12

3090 is pretty power hungry I'd say high quality branded 750w minimum really.

You might...get away with lower but you'd be pushing your luck.

I decent quality branded 850w would put you in a good comfort zone.

Edit: if you want to get technical you need to lookup the peak draw in amps, of that card, then make sure the PSU can deliver that, with a bit of wiggle room, check the PSU has a single 12v rail.

mickyflinn · 17 Dec 2021 at 12:43

850w but i would Get a 1000w psu the power spikes can be big on 3090 and the 12900k can draw big numbers especially overclocking.

Djwayne · 17 Dec 2021 at 12:54

So something like this would do the job?

https://www.overclockers.co.uk/seas...w-80-gold-modular-power-supply-ca-07x-ss.html

Last PSU i bought was for a Sandyubridge rig back in 2011 and i think that was a 750w looking at todays numbers that may have been overkill.

ODuffer · 17 Dec 2021 at 13:08

RM1000x is a good shout as well

dave28 · 17 Dec 2021 at 13:16

1000w probably, those new intel cpus pull stupid watts if overclocked and that gpu eats watts also.

maybe be fine with 850 also though

Grimley · 18 Dec 2021 at 08:27

Cheapest Decent on OCUK:

My basket at Overclockers UK:

1 x Corsair RM Series RM850 850W '80 Plus Gold' Modular Power Supply (CP-9020196-UK)= £84.98

Total: £93.68 (includes shipping: £8.70)

OvEr_KiLL · 21 Dec 2021 at 15:28

seasonic 10 year warranty https://www.overclockers.co.uk/seas...w-80-gold-modular-power-supply-ca-07x-ss.html
or the phanteks 12 years also made by seasonic https://www.overclockers.co.uk/phan...old-modular-power-combo-supply-ca-08b-pt.html

Preytheon · 21 Dec 2021 at 15:48

Nothing under 850W, given those two components: the Intel CPU's have some really extreme power spikes when they're on boost.... and the RTX3000's are well known for some pretty solid bursts too - anecdotal evidence suggest both will spike above their quoted maximums. Once you add the Z690 chipset and a few other bits, even an 850W will need to have a perfect balance across the rails to stop it tripping.

Darujhistan · 31 Dec 2021 at 19:03

With that setup, you want a top quality 1000w unit.

Preytheon · 31 Dec 2021 at 22:02

1000W would probably be slight overkill.... but not crazy if there's any overclock on that CPU.... and I suspect with the over-spec'd PSU, it's more likely to stay in the fanless mode (for those PSU's that support that)....

EsaT · 1 Jan 2022 at 09:50

Preytheon said:
1000W would probably be slight overkill.... but not crazy if there's any overclock on that CPU.... and I suspect with the over-spec'd PSU, it's more likely to stay in the fanless mode (for those PSU's that support that)....

Not really.
Despite of public hallucination NVidia's high end cards haven't been power frugal in years.
And 3090 FE is capable to drawing ~360W as average, with continuous 550W peaks:
https://www.igorslab.de/wp-content/uploads/2020/09/8a-Gaming-Zoom-Power-1.png
(that's 20ms duration)