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750 watt PSU enough for a 9900k & 3090

Associate
Joined
28 Jan 2015
Posts
680
light gaming, no overclock- will it have enough power as question asks?
Needing to relocate to a smaller case and only take a SFF and 750w seems biggest one Ive seen
edit: just seen a 850w one
 
Associate
Joined
26 Apr 2017
Posts
1,255
light gaming, no overclock- will it have enough power as question asks?
Needing to relocate to a smaller case and only take a SFF and 750w seems biggest one Ive seen
edit: just seen a 850w one

two things you dont want to skip on, mboard q and psu power.
850w can be enough but random spikes and what not can happen.
1000w or more I would go for.
 
Soldato
Joined
16 Jun 2004
Posts
3,215
9900K & 3080 owner here with a Corsair RMx 850w PSU...no issues whatsoever and the 3090 doesn't pull that much more power than a 3080.

Even at full load I doubt my entire rig pulls more than 550w.

GPU tops out at ~320w (100% load), CPU @~170w (100% load in Cinebench runs) and everything else ( 5 fans, 4 HD's, 8 USB sockets in use) and that's only when running flat out, which no PC does 90% of the time, unless you're a full time video encoder or 3D renderer, in which case what the hell are you using a 9900K for :)
 
Soldato
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9 Mar 2015
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4,550
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Earth
Been using the 3090FE with 9900k with corsair 750w SFX unit for nearly a year now.

With that, in 4k gaming, will usually sit around 450w-525w total power draw with 3090 set to 400w and 9900k at stock. With quality units like the SFX 750w even if there are spikes, it copes with it fine. That said, there is 850w so grab that, but for me 0 issues with the above, that's with about 500 hours of play with GPU pegged at near 100% in most cases as its 4k 120hz screen so all horsepower needed in most games like CP2077 etc.
 
Associate
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21 Jun 2011
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1,026
Location
London
Power usage is an average over a given period of time, so power spikes are naturally included in the rating. It's the actual physical quality of the components that matters.

A higher powered unit may last longer because of capacity, but that would fall within the warranty. A warranty is only beneficial if you actually use it.

Unless you know your components need additional power, the manufacturer's recommendation should be sufficient.
 
Associate
Joined
25 Aug 2005
Posts
613
10700k with a mild overclock and a stock 3090 FE pulls 500-550w while gaming at 4k with all the bells and whistles turned on. Add some for spikes. Got an Asus 850w and had no issues.
 
Associate
Joined
30 Jun 2006
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1,221
Location
Cardiff
I use a sff power supply rated at 750w. I have a 3080ti which I have seen alone draw 430W when left toward its own devices. There is only 3 Psu brands I will stick in my builds Corsair AX series non digital, Seasonic and Corsair sff series.
 
Associate
Joined
5 Mar 2017
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Location
Cambridge
3900x + 3090 and plenty of watercooling gear was fine with a solid 750W, but the efficiency curve would be more favourable on the 850W. Also the main issue with the 3080/3090 isn't only power consumption, but spikes. A 850W would have some more margin before those power spikes causes any issues/random reboots.
 
Associate
Joined
5 Mar 2017
Posts
2,252
Location
Cambridge
I use a sff power supply rated at 750w. I have a 3080ti which I have seen alone draw 430W when left toward its own devices. There is only 3 Psu brands I will stick in my builds Corsair AX series non digital, Seasonic and Corsair sff series.
Tried Corsair and wasn't really happy with. Seasonic is as solid as a tank on their top tier ranges.
 
Associate
Joined
11 Jan 2021
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1,099
Tried Corsair and wasn't really happy with. Seasonic is as solid as a tank on their top tier ranges.
i have a corsair ax 1000 titanium and am trying to figure out how its possible to be unhappy with a power supply, about the only thing i can say about corsair power supplies that might be a pain is the cables are very stiff with the caps in it makes them hard to get where you want them to go



i mean unless this is about a sff range specifically then i dont have any experience with those as i dont build a pc in a shoebox
 
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