About one week ago I swapped out my Nvidia 3090 for AMD 7900 XTX. I used the Topaz benchmark tool before/after the change. The video card was the only change I am aware of to the system.
Comparison using the 1920x1080 (FHD) Benchmark:
Comparison using the 3840x2160 (4K) Benchmark:
As shown, the 7900 XTX is not as fast, but there may be other tradeoffs not yet considered, E.G. power consumption and heat (of which the 3090 has plenty, and the XTX seems to not sweat it too much no matter what it’s doing). Maybe/maybe not, I just don’t know. I am glad I switched because it is significantly faster in some VR games I use my PC for, and so that was worth it. I’ll just have to be a little more patient with my video work until optimizations are made. Oh, the tradeoffs! 
