Does a 6900XT really need a 900w+ PSU?

[mikehhhhhhh]

I've just picked up a Powercolor 6900XT Red Devil and the minimum PSU requirement is 900w!

I don't mind overspeccing, but I can't find a 1000w PSU anywhere. Does it really need that much power with a 300w power limit?

The rest of the system consists of a 5800x, a couple of SSDs and 4 fans, so not exactly heavy!

 

[mikehhhhhhh]

What PSU do you have and what are your other system components?

I don't have any PSU currently, this is a new build.

As above, 5800x, 2x SSDs, 4x case fans - oh and a 280mm AIO with 2 fans.

 

[mikehhhhhhh]

No, do not think so. I went through a PSU calculator the other day involving that card and 5900x. Believe it said 750w.

My suspicion is that a good quality 850w PSU will be just fine, but I ideally wanted to hear from someone running an overclocked/AIB 6900XT to be sure, instead of taking a gamble.

 

[mikehhhhhhh]

If I went 850, I'd proabbly apply a similar budget and go for something like this Asus Platnium PSU

According to Kit Guru it can handle a peak loaf of up to 965w.

 

[mikehhhhhhh]

There are better PSU that that. You can get a nice 1000W platinum for 200£

https://www.overclockers.co.uk/be-q...-platinum-modular-power-supply-ca-13y-bq.html

Sure, but all out of stock everywhere - hence this thread

 

[mikehhhhhhh]

I have the Red Devil 6900XT. I am running it on an XFX Gold rated 850 PSU and it's absolutely fine. I often run mine with an aggressive overclock, using up to 325W. My benchmarks are competitive too if you have a look at the Firestrike benchmark threads, you'll see me near the top. I'm also using a 125W TDP 5800X chip, high frequency RAM and 6 SSDs. I would say you'll be fine with a gold or platinum 850 PSU.

Thanks - that's just the experience I was looking for.

I took a gamble and ordered the Platinum ROG one I linked above, which did 965w in Kitguru's test.

 

[mikehhhhhhh]

Damn fine looking PSU that! I really want one but you wouldn't be able to see it in my case.

Sadly it'll be hidden away in mine also

 

[mikehhhhhhh]

I would take heed of these Transient Spikes as the 3090 is the same, some 850w will work and others give you issues, I repeat again that one member here had an 850w with 2x 1080Ti for years with no issues then crashes on 1x 3090 till he swapped to a 1000w.

Crashses as in power offs with over current protection, right?

 

[mikehhhhhhh]

Not 100% sure as I do not have issuew as have a 3090 on a 1600w, but I could search the posts and reread.

Interestingly, I also have a 3090 on a Corsair 850w PSU.

It's fine on every game I've played, but Cyperpunk will crash out consistently after anywhere from 5-30 minutes play.

I can't imagine it's PSU related, though, as I'd have thought over-current would be cutting power not causing instability.

 

[mikehhhhhhh]

I have a 3090 on a Corsair 750w with a 3900x and it runs great. I doubt your psu is causing it to crash, likely just the game which is buggy.

Thanks, that was my assumption to be fair.

yes if it didnt they wouldnt say that it did mhm

You think it needs the same size PSU whether it's got a 10900k that'll pull 300-330w or a 5800x that'll pull 120-140w?

 

[mikehhhhhhh]

The 900w assumes you're gonna use your 6900xt which is a top of the line gpu with a top of the line cpu and even overclock it cause that's normally what people who spend 2k on a gpu would do. If you're one of those who pair entry level parts with top of the range parts then sure you can figure out your own psu requirement, you can even underclock your gpu to lower your pay some more

The 5800x has the same power limits as the 5900x and 5950x, though.

Also, I certainly didn't spend anywhere near £2k on any GPU

 

[mikehhhhhhh]

Well I got a chance to game on the 6900xt properly today.

I spent 1-2 hours on Cyberpunk without a single crash.

That's on the 850w Thor PSU and Power limit maxed out - it seemed to hover around 330w according to Radeon overlay.

It'd be interesting to try the 3090 on this PSU and see if the crashes in CP go away.