Overclocking Options

All Intel CPUs are currently clock multiplier locked, However you can still adjust the Front Side Bus for now. Intel has yet to come up with a way of locking that up and bringing it to market at a low enough price (which is good for us).

This means that as long as we stick to the Pentium III-450's 4.5X clock multiplier setting, we can increase the clock speed by increasing the bus speed of our motherboard. Here's a look at some possible overclocked speeds that the Pentium III-450 could see when using our Abit BX6 2.0 motherboard.

4.5 x 100MHz = 450 MHz
4.5 x 103MHz = 464 MHz
4.5 x 112MHz = 504 MHz
4.5 x 117Mhz = 527 Mhz
4.5 x 124MHz = 560 MHz
4.5 x 129MHz = 580 MHz
4.5 x 133Mhz = 600 Mhz

The Pentium III-450's 4.5X multiplier give us a nice speed range to play with. To do the overclocking test, I removed the stock Intel heatsink (not an easy task) and put on Global Win's new VEK 18 cooler that I got from AMK Services. The VEK 18 is a VEK 12 with more powerful fans (they move 26CFM of air each!!). The VEK18 is really a Pentium II cooler. It wasn't designed for Pentium IIIs. I made it work on the Pentium III-450 by removing the the VEK 18's PII mounting clips and tying the unit directly to the Pentium III-450 with Zip Ties. Hey! It's works! :-)

Here are the results of my overclocking test.

4.5 x 100MHz = 450 MHz - 100% stable at 2V
4.5 x 103MHz = 464 MHz - 100% stable at 2V
4.5 x 112MHz = 504 MHz - 100% stable at 2V
4.5 x 117Mhz = 527 Mhz - 100% stable at 2V
4.5 x 124MHz = 560 MHz - 100% stable at 2.2V
4.5 x 129MHz = 580 MHz - 100% stable at 2.2V
4.5 x 133Mhz = 600 Mhz - POST, loads Win98, but not stable.

WOW! With just a $20 heatsink, the Pentium III-450 loaded Windows 98 at 600Mhz and was able to run a few benchmarks before it randomly rebooted itself. It did a 290 on the Norton benchmark! 600Mhz is not a stable option with this CPU. However it runs 24 hours a day at 580Mhz. I let it run Prime 95 overnight and when I got up the next morning, it was still going!

I don't know if this Pentium III-450 represents what all Pentium III-450 can be overclocked to. I have 2 units and both will do 580Mhz at 2.2V.     I may just have lucked out and got some really good examples. From other reviews I have read, it would seem that the CPU should be able to run at least 560Mhz with a good heatsink, which is nothing to sneeze at. I'm sure if I cool the L2 cache and use a bigger cooler like the Alpha 125, I can get the Pentium III-450 stable at 600Mhz.

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