So it's been a month with this GPU and I've been kinda dissapointed. The only games that I can play properly are CS:GO and League of Legends. Other DX11 titles are a mess: my GPU usage is low so I get either low fps, frame drops or stuttering.
I've tried remounting the GPU, overclocking, downclocking, setting the power limit settings up or down, replacing the PSU, reinstalled drivers (15.7.1, 15.8, 15.9 and the ones that came on the CD in the GPU's package), fresh installed Windows and so on..
In idle, the GPU never went above 60C, and in games, the most I had was 75C. In Unigine Valley it reached 80C though.
In Unigine Valley this is the score I had, which was pretty dissapointing: http://i.imgur.com/h0fBVZr.png
Here you can see my problem: Low GPU usage/Low FPS/FPS Drops/Stuttering [MSI R9 390X] - YouTube
The thing is I even play at 768p in the video above, even though I encouter the same problem at 1080p.
Windows 8.1 Pro 64bit
AsRock H87 Fatality Performance
MSI R9 390X
8GB RAM 1600MHz
700W 85% 80+ Bronze
Thank you in advance guys!