Here's the story:
I got a new Q9550 to replace my E7400. So I put it in, and it worked. I overclocked it instantly, set the multiplier to 8 and the FSB to 400. It booted up fine, and I played CS:GO with it. No crashes, etc. But I was getting unusually low frame-rates for a quad-core (70-90, same fps as my previous processor). So I removed it, checked to see the pins, and one pin was bent. I was surprised that it even worked. So I fixed the bent pin using a needle, replaced everything back, and everything was back in track. The FPS skyrocketed to 150+ fps, even reaching 200+. But it still dropped to 40 near smoke, so I went back to the BIOS to overclock. Set the multiplier again to 8 and FSB to 400. Now, when I boot the PC up, the artifacts just pop out, the OS stops responding, then... BSOD.
Can anyone tell me what the underlying issue is? Mobo is an ASUS P5KPL-AM EPU. PSU is a 500W Powerlogic.