Nästan nytt corsair SF600 V2 mot annat SF nätaggregat 650+

How many watts do you need or want? What size would suit: SFX, SFX-L, ATX or what? Can you say why you need more than 600W in (presumably) an SFX build?

From what I read, a 2080 Ti would draw less than 300W and a 3700X is easily less than 150W when sensibly overclocked. Even a 3950X with 16 cores also draws less than 150W (without overclocking in that case, but this is an SFX build after all). Your CPU cooler in your SFX build is probably a bigger limitation because the latest Ryzen CPUs need to run cool to run fastest. Perhaps your SF600 V2 is actually plenty, after all.

Your ITX or DTX motherboard and one 2080Ti also probably can't use more connectors than the SF600 V2 provides.

Just trying to help there, in case you don't need to change PSU actually.