MSI GTX 970 4GB. Low fps in games!

Hi all changed the RADEON HD7850 to a GTX 970. I thought that my sufferings were over and finally we can play a calm soul! But alas! Gives low Fps, even worse than on RADEONe: GTA 5 - issue 20-25fps(and below). Same with THE WITCHER 3 and most games. Moments when the character is idle, just standing, even the camera does not twist 40-50 fps. As soon as the camera will move fps drops to 10 and below! And it sceti in all games.
My system ( not top of course but pulls ):
CPU: xeon e5450 3.0 Ghz
Video card: GTX 970 4gb
Operational: 4ram (here most likely because of the low memory problems I guess)
Power supply : 650w
Driver latest, Windows 7 64bit only reset.
Through control of the graphics card settings set to performance. No change!