I've had my intel E6750 (stock 2.6ghz) overclocked to 3.2ghz just by changing the FSB to 400 with a multiplier of 8 for probably over a year now. I just went to put in new ram (4 gigs of ddr3 1066) and when I did, I saw the CPU overclocking was reset. I tried to put it back to 8x400 and it wouldn't take. I put the old ram back in (2 gigs of ddr2 1066) and the CPU still won't overclock. I even raised it by 1 single mhz and still nothing. What could be the problem?
Somehow I managed to be stabled at 2.8ghz and right at this moment I'm at 3.0ghz, haven't stressed it yet or anything, but it booted.
I was looking at my old files and I saw at 3.2 ghz I used to be at 32*C for my CPU. Right now I'm at 48*C. Sounds like an overheating problem. I haven't touched it at all, but I'm thinking something could have happened to the thermal paste? The fan is still tightly secured.
Sorry yes, I left out that those two temperatures were at idle. I ran Prime95 and within 1 minute temps were exceeding 67*C, which was the max temp hit in the 4 hour session I did when I was first overclocking.
Just an update: So I'm not sure what the deal is, but I tried slowly upping the bus speed, and I was at 375 MHz for a week or so no problems. I reapplied thermal paste to the CPU/heatsink, figuring that might have been a problem since it was last applied 3 years ago. About 3 days ago I upped it again to 400 MHZ, and again no problems. So right now I'm back at 3.2 GHz.