I have an issue with G Skill F4-3000C15D-16GVRB RAM.

After applying XMP profile on BIOS the RAM seems to be stable at 3000 MHz.

But after a few hours with intensive cpu using game, the RAM is not stable any more and PC freezing.
Using default speed don't have any issues.

My motherboard is Gigabyte Z170 Gaming 7 (latest bios).

The CPU, 6700K is slightly overclocked to 4.4 and stable.

Please help to solve this issue.