Which PSU Should I Get?

[Vic 40]

if the GPU needs 500W (something I just noticed said 255W MAX) then why does my card's documentation say that XFX recommends 850W and the bare minimum is 750W? If the GC actually uses 850W at times (assuming 90% efficiency and factoring in the other components of my system), how would it be possible to run my system on 850W without causing brown-out/throttling conditions?

Recommendations for psu power is for total system power, not just for the gpu and they do include a substantial overhead.

Think btw that Phaaze got confused by the response from zszabo who started to talk about the 4090, it did confuse me too.

 

[Phaaze88]

@Phaaze88 I'm really not sure why you keep talking about a card that I don't have (4090, 5900). I thought you were using it as an example about wattage, but now I think you might've gotten my setup confused with someone else's. I have an XFX Speedster Swift 319 Radeon RX 6080 XT 16 GB GC. In fact, I am unaware of anything in my setup that is so new that I qualify even vaguely for the statement that I'm asking for info that's not available. Am I correct that you mixed me up with someone else, or is my GC truly that new? If it's the latter - I truly had no idea that I had a card with an "older" GPU on it that is new.

/facepalm What have I done..?
I am definitely not helping.

Ahem! Taking another crack at it:
1)1000w unit with a RX 6800XT? That's quite the overkill, IMO. The discontinued AX850 I'm using would be plenty for that card.
Assuming the SWFT is similar to the MERC and some other 6800XTs, the transients can't be worse than models like the 6900XT, 6950XT, RTX 3080(and up) manage to nail.
6950XT Formula
3080 12GB Suprim X
6900XT Gaming
6800XT Gaming X Trio
Looking through these samples and others(screw Furmark), the AIB models were almost always worse in transients than Founder's or AMD Reference - where present. Not really a surprise when factory OCs are involved.
The cpu isn't going to use that much power in games. Maybe 100w in some - if that, in others. Everything else in the PC pales in comparison to those 2.
So if a 6800XT SWFT is ~290w total board power - with up to 350w for transients, add 100w for the cpu... that's 450w total. 100w should cover everything else... now, it's at 550w.
Overclocks will of course, make the cpu and gpu worse on power for little gain.

2)Futureproofing - if that was part of the agenda - does not work. Get something within reason and don't play with a concept that you're scripted to lose the extra cash spent.
3)Corsair RM850X, and call it day.

 

[ReveurGAM]

Recommendations for psu power is for total system power, not just for the gpu and they do include a substantial overhead.

Think btw that Phaaze got confused by the response from zszabo who started to talk about the 4090, it did confuse me too.

You're exactly right, I believe, Vic. I'm asking about system power but keep getting responses that only seem to consider my GC. Thanks!

 

[ReveurGAM]

/facepalm What have I done..?
I am definitely not helping.

Ahem! Taking another crack at it:
1)1000w unit with a RX 6800XT? That's quite the overkill, IMO. The discontinued AX850 I'm using would be plenty for that card.
Assuming the SWFT is similar to the MERC and some other 6800XTs, the transients can't be worse than models like the 6900XT, 6950XT, RTX 3080(and up) manage to nail.
6950XT Formula
3080 12GB Suprim X
6900XT Gaming
6800XT Gaming X Trio
Looking through these samples and others(screw Furmark), the AIB models were almost always worse in transients than Founder's or AMD Reference - where present. Not really a surprise when factory OCs are involved.
The cpu isn't going to use that much power in games. Maybe 100w in some - if that, in others. Everything else in the PC pales in comparison to those 2.
So if a 6800XT SWFT is ~290w total board power - with up to 350w for transients, add 100w for the cpu... that's 450w total. 100w should cover everything else... now, it's at 550w.
Overclocks will of course, make the cpu and gpu worse on power for little gain.

2)Futureproofing - if that was part of the agenda - does not work. Get something within reason and don't play with a concept that you're scripted to lose the extra cash spent.
3)Corsair RM850X, and call it day.

Thank you! Ok, so I guess the manufacturers all over-estimate the power needs and needlessly drive up the purchases of higher-powered PSUs is what you're saying...Right? Sigh. So that would explain why the 4 or so part pickers I used all lowballed my power needs between 650-850.

 

[Phaaze88]

Thank you! Ok, so I guess the manufacturers all over-estimate the power needs and needlessly drive up the purchases of higher-powered PSUs is what you're saying...Right? Sigh. So that would explain why the 4 or so part pickers I used all lowballed my power needs between 650-850.

It's in their best interests to exaggerate. There's so many different possible configurations, and everyone doesn't use their PC the same way. Some will have less than ideal psus as well, so the higher wattage MIGHT help.
I know some of the manufacturers get their ratings from Furmark. This program does not accurately represent game behavior at all. If there's any purpose to it, that's seeing how strong the cooling solution is.

 

[Vic 40]

Can't really blame manufacturers for overestimating the power requirements , but that also doesn't mean for the parts you picked that you need a 1200watt psu for instance. The 850watt estimate is perfectly within reason.

 

[ReveurGAM]

Thanks, @Vic 40 & @Phaaze88!

 

[ReveurGAM]

I thank everyone who has contributed to this discussion, especially those of you who have broadened my understanding of PSUs. I've ordered the RM850x.