Hello! I just recently installed RivaTuner 2.05 (with the signed driver package) to try to overclock my GeForce 8800GTS under Vista Ultimate x64. My problem is that while everything seems to work normally, overclocking does not seem to take effect. I can adjust the sliders any way I want, but there is neither any difference in 3DMark score or in game performance. I'm having the same problem with nTune - I can adjust the frequencies at will, but nothing happens. I'm using driver version 163.69. Is there anyone else with similar experiences? My system: Corsair 620W PSU, Athlon 64 X2 4200+, 4 GiB of DDR-RAM and XFX GeForce 8800GTS 320 MiB.