I build a new PC based on 4650g couple of month ago and I have a problem since then. When I trying to use XMP profile - GPU starts glitching and freezing. I first thought, thats cause of defect memory, so I changed from Corsair to HyperX - and it works even worse - PC completely freezes on Windows loading screen with graphical glitches and even in BIOS. It works more or less stable on 3000MHz and auto settings (so it makes 22 timings, instead of 16 on XMP). Is it because of defect GPU core in 4650g or something wrong with motherboard's BIOS?