There is something wrong with the F5 Bios, i been using F5q before and suffered from the same. And the issue seems to be in the Final version of F5 aswell.
What happens can be compared to a "Driver has stopped responding" issue. Screen goes black then comes back on, but the Framerates are completely screwed up (10-15).
When it happend when i used F5q i first thought it was a TDR issue, but after rebooting the PC the Framerates in Games were still between 10-15. The only way to fix it was to flash the Bios back to F4. I used that for like 4 weeks without a problem. Today i saw the final of F5 was out and thought id try that again, but just 5 minutes ago the same happend and once again rebooting doesn't solve the problem.
No idea what the issue is, but i'm going back to F4.