Thanks,
@zipzoomflyhigh
I removed all NVidia drivers/files with driversweeper
It was Tagan, about 450W, 2 rails +12V (20A each), with a switch doing something with dividing the power among rails,
but in both positions the problem was appearing.
Do you think these PSUs could be too weak for such system?[quotemsg/]
I have a Gigabyte 5770 and they recommend a psu with a 12v rail with at least 24 amperes. My 620w psu has 24 amperes on each of it's 2 12v rails and it works fine. With 20'amperes on that 12v maybe the gpu isn't getting enough juice?