I'm really becoming obsessive about this problem, since I couldn't figure it out on my own or using google in 2 days, so here it is:
I've bought a new GPU a week ago (hd 4850=>hd 5850 toxic) and since I knew that my old CPU (E5200) would bottleneck it, I bought a Q8300.
So, all goes well, I put it in, thermal paste and everything, I turn it on, and it FREEZES under games, or even a flash video (if bsod=restart is enabled in windows, it would restart the system).
I could not figure out why, the first thing I thought that my memory couldn't handle it. But why couldn't it? It's a DDR2 2x1gb+2gb 800Mhz ram, so I thought, maybe it doesn't like the dual-channel+single channel thing.
Okay, I tried every combination of removing the RAMs, but it didn't work.
The Q8300 is @ 2.5Ghz not OC'd, with a 333 FSB, that means my DDR Mhz of the ram is at 667, so it REALLY should handle it.
Then I thought, maybe the PSU can't handle it, so I swapped back my old HD 4850, then it should be really working, but the same error.
Finally, how about a Win7 reinstall? I tried it on my x86 and my x64 already-installed OS, same result.
I reinstalled my X64, still, same.
I ran prime95 for about an hour with no stability issues, hell, I even ran Prime95+Furmark symultaneously, it was rock solid.
I start a game, for example Tribes:Ascend or Painkiller HD, after 1-3 minutes, it freezes.
My full system specs:
PSU: Corsair VX450W (Yes, using a molex-to-6pin-pcie for the second slot on my 5850 and it had no problems)
Motherboard: MSI P43 neo-f (Upgraded bios to latest version)
CPU: Old: E5200 New: Q8300 (Intel core 2, LGA 775)
GPU: Old: Sapphire HD 4850 New: Sapphire HD 5850 Toxic
Memories: 2x1gb Corsair DDR2 800Mhz + 1x2gb Kingmax DDR2 800 Mhz
Storage: 2 SATA HDD-s
-while prime95 ran, the max CPU temp was 60 °C, but that shouldn't be a problem.
-FSB/DRAM ratio is 1:1
Download WhoCrashed, it gives you a general idea of what your problem is if you BSOD. It looks at past crashes before you got it too so you dont have to wait for another one. Other than that try and put the C2D back in and see if it still does it. If it does then it is your motherboard and you need a new one.
I have found a correlation between the memory freq and the speed of the incoming crash.
A month ago, when I still had the E5200, the bios resetted and accidentaly the fsb wasn't at 1:1, it was at 1:1.20 or something, so the Dram was around 600Mhz instead of 480 Mhz and it couldn't handle it. Now due to the quad core, the 1:1 dram freq. is 667 Mhz.
I'll still not give up just yet, how can the memory be tweaked and where?
Also, voltage is on safe mode (grey), should I up it a little?