Hello, yes i used same version, aida64 3.20.2600. I just installed windows 8 x64 to test battlefield 4 beta, because dont run well in windows 7. Beyond aida64 i tested winrar performance, and there too i got worse performance compared to windows 7.
Winrar performance decrease from 4000-4100 kb/s in windows 7 x64 to 3600-3700 kb/s in windows 8 x64. Using same version 4.20 x64 winrar.
I dont know if matters, but i installed each OS in differente HDD, but them have same 7200rpm, windows 7 in 500gb segate and 100gb for OS partition, and windows 8 2tb seagate 200gb for OS partition
So im confused, maybe windows 8 is a heavy OS?