Similar story but oddly didnt notice it with the 5800X, just that it wasnt quite smooth as the 5800X3D.
I put it down to running my 5800X at 1900IF 1:1 with 3800Mhz RAM and now the 5800X3D can't do 1900IF its best leaving XMP for 3600, 1800IF
I tightened up my timings and put a nice little undervolt on my 3080 and between them i'm getting a very stable 135-140 (limited at 140 because of my g-sync screen 1440p) with dlss quality. gpu usage is less than 100% so could probably bump it to dlaa if i wanted too. afterburner says the CPU is using about 70 watts - which i find incredible!! Still rubbish at MW2 though!!!