Hi. I have mentioned board (for 2 days now) rev. 1.0, bios F3 version, Gigabyte nforce 6600 VGA card, 1 stick Kingmax DDR2 800MHz ram and core 2 duo 6400 cpu. I haven't changed anything in bios (C1, EIST and so on, everything is on default) and managed to reach 396 X 8 (around 3200 MHz) without raising any voltages. Everything works OK, the machine is stable but once in standby STR mode I can't make PC to wake up again (to be more precise - HDDs spin up, fans are working but LCD monitor doesn't start, neither the external USB HDD drive. When I force shutdown by pressing the power-up button, PC tries to power-up by itself over and over again every few seconds so I have to switch of the power-supply button. After that PC boots normally again. I have noticed that standby led diode doesn't flash but I am not shure if this have anything to do with my problem. When not overclocked PC wakes up normally (although a little bit slow when compared to my other platforms) Thanks in advance.
So, finally I managed to reveal the cause of such behaviour. I flashed to the newest F7 bios but the bios version wasn't the cause except it explained to me in its "optimized settings" for voltages under I.M.T. that gigabyte's bios automatically raises voltages in order to increase stability when overclocking. That also explains unusually high temperature readings I was getting in idle (about 50 C). Obviously the DIMM voltage was to high for my Kingmax ram and, when overclocked over certain degree, it refused to wake up from standby mode (strangely, when powered up, everything was OK). Now I have set "manual" mode instead of "auto" and all voltages are at default level, the cpu temp. is 51 C at full load in Prime95, and fortunately my overclock is still @3.2 GHz although the voltage is lower. Bye.