Overclocking the P3-600

The Specs

Here are all the numbers off our processor for you information junkies.

Top of the processor:
600/512/100/2.0V S1
99270194-0460 MALAY
I(m)©'98 SL3JT

The cache:
M5M5V2236BGP
921BE0L -3H
300MHZ

P3 overclocking

All the current Pentium II processors operate on the 100MHz FSB, and the P3-600 is no different. It uses the 6.0 multiplier for the 600Mhz (6 x 100) clock speed. All Intel processors are "clock locked" which means you cannot adjust the multiplier settings, but you can still adjust the FSB speed to overclock your P3. For example, you can bump up the FSB speed to 105 to make your processor run at 630MHz (6 x 105).

Let the overclocking begin!

We used the Abit BE6 in our overclocking attempts because it offered the 105, 110, 112, 115, and 120MHz bus speeds. We didn't expect to reach the 124MHz FSB, because 744MHz (6 x 124) was beyond the estimated theoretical speed limit of the .25 micron Katmai design. We used a single 64MB stick of 8ns RAM that could go up to 124MHz without any problems.

We started with the factory heatsink and fan just to see how far we could take the processor with the standard cooling. We only gave the 630MHz (6 x 105) speed a cursory test just to see if it was able to boot into Windows. It worked fine, and the processor made it through several benchmarking programs without a problem.

We quickly moved onto 660MHz (6 x 110). The system was able to POST, and boot into Windows, but it would crash if we tried running any strenuous benchmarks. This looked like a heat issue, and we tried swapping the factory heatsink/fan with a more robust model from our P3-500. We dabbed on a little thermal compound, attached the new heatsink/fan, and we were good to go. The system was very stable at 660MHz after the heatsink/fan switch.

Next we tried 672MHz (6 x 112). The system could POST and make it into Windows, but it couldn't make it through any benchmarking programs. We tried increasing the voltage, but we went all the way up to 2.3V without little improvement. Not surprisingly, 690MHz (6 x 115) gave the same results. The processor couldn't POST at 720MHz (6 x 120). We feel that our test processor could probably do 672MHz or 690MHz with some extra cooling.