Accidental Overclocking of Intel CPU

[LeadReckoning]

I am a newbie and have not tried any overclocking. On the last system I built, I was working with an Intel 1600 CPU. In the bios, I accidentally set the multiplier to 12x133. When I ran 3dmark, the system seemed stable and I got a score of 9200. I next ran Sandra and it told me that I had a non-standard setting for the multiplier. I changed it to 16x100 and again, the system seems stable. Now when I run 3dmark I get a score of 8300. My question: what did I do and is it harmful? As I said, the system seemed stable. Thanks for helping a newbie.

 

[cnhoff]

I guess you are talking about a P4.

Since this cpu has a locked multiplier, only the FSB is taken into account when you change anything in the BIOS. A P4/1600 has a multiplier of 16 so with 12*133 your cpu was running at 16*133 = 2128. With 16*100 it was running at its (native) 1600 MHz freq.

That's why you got a higher score in 3Mark at the first run, because your cpu was higher clocked and your FSB and RAM had more bandwidth.

Hope that helps!

P.S. Overclocking is seldomly harmful, the only thing that can happen is, that your system locks up. I wouldn't go to high with the core voltage though, that CAN damage your cpu. But I think you didn't change cpu voltage at all.

 

[LeadReckoning]

If the system seems stable (and I don't know if that's likely), is there any reason why I should not change it back to 12x133? Will this harm my video card, memory or other components?

 

[cnhoff]

Do that, there is no reason to get more ouit of your money . If the system is unstable back down the FSB by small increments until it's stable.

 

[Jhhnn]

The multiplier setting in the bios means nothing- an Intel cpu ignores it completely, runs according to its own internal locked multiplier. Your 1600 is often an excellent overclocker, so if it remains stable at 133fsb, leave it there for a free performance boost.