Question Keeping old psu with 4090

[Delhu]

Hi guys,

I'm looking to update my gaming build.
I have a Super Flower Leadex platinum 850w (SF-850F14MP) that I purchased back in 2015 that I'd like to keep if possible.

I'm going for a 9800x3d with either a used Gainward Phantom GS 4090 (purchased from family) or a brand new 5080 (leaning towards a palit gamerock oc). Rest of the build will have 2-3 ssds (1 msata, 1-2 nvme, i'll probably ditch my hdd), liquid cooling for cpu, all within a Corsair 750d.

As you can guess my questions are the following:
- can my psu handle the 9800x3d and 4090? I saw that it is a tier A psu, and that guru3d recommended at the time a 850w psu in their review of the 4090. In forums, people are split between it is enough and "don't cheap out on the psu and get at least 1000w".
- have gpu connectors changed since 2015 ? I saw the stories on the new 12v connectors that burned on some 4090s.
- bit on the fence about getting a used gpu. Is the additional vram really better than getting dlss4 (and lower consumption)?

Thanks !

 

[Hellfire13]

Its no doubt a very good PSU and definitely good enough for the build. But 10yrs is a pretty long time for even a PSU. That should be a concern, depending on how much it has been used.

 

[VizzieTheViz]

I’d get a new psu if the one you have is ten years old. That’s end of warranty even for the best psu.

Also 4090 is better in most ways than 5080, especially if you want to game in 4K where the horsepower and vram really shine.

 

[logainofhades]

I would recommend getting a new PSU as well, and keep your current one as a spare.

 

[Eximo]

I'm in the same boat. 2016 RM850X, have to start shopping now I suppose.

 

[Delhu]

Its no doubt a very good PSU and definitely good enough for the build. But 10yrs is a pretty long time for even a PSU. That should be a concern, depending on how much it has been used.

Hmm, I've never thought about replacing it because of its age. When they stop working, do they just stop or do they put other components at risk?
Hard to say, roughly 15-20h a week on average. PC was always powered down when not in use.

 

[USAFRet]

Hmm, I've never thought about replacing it because of its age. When they stop working, do they just stop or do they put other components at risk?
Hard to say, roughly 15-20h a week on average. PC was always powered down when not in use.

Yes, a dying PSU can compromise, or even kill, other components.

Replace that decade old thing.

 

[Delhu]

How much wattage do you recommend in 2025? 1000 or 1200w ?

 

[VizzieTheViz]

How much wattage do you recommend in 2025? 1000 or 1200w ?

I can’t really imagine even a 5090 needing more than a 1000w psu, maybe if you’re using multiple gpu’s and a really power hungry cpu you’d need something more powerful.

 

[Hellfire13]

Good quality 1000w should be plenty.