I have seen a video (German YouTube) who tested this riser and it didn’t worked.Haha never mind. I just realised it's the same one as linked a few posts back..
PCIe 4.0 is a Little tricky with riser cables. Maybe someday the big manufacturer like fractial, NZXT etc. Will make a working cable that’s affordable. Unless I would be sceptical.
Maybe this is all just a wishful thinking that you get that high performance bump out of 4.0 I mean the SAM mode from amd isn’t even out yet and we break our heads about the risers. Even gamers nexus showed that you don’t really lose performance with a gen 3 riser. Let this Sam mode mature and maybe than we have good 4.0 cables that maybe will give a performance bump