The following chart shows examples of AMD processors that were hooked up to our water cooling system and overclocked. During the testing procedure, the temperature in the water block was a constant 24 degrees - the best cooler in our last comparative test (Can't Touch This! A Comparison of 46 Coolers ) managed a mere 30 degrees. We used processors from 750 MHz to 1333 MHz, overclocking them by simply increasing the clock multiplier. Had we also increased the front side bus, the results would probably have been even better, but the system's stability would have begun to suffer after a brief while. One thing is quite clear - the AMD Duron 750 is the processor with the best overclocking rate. A 30 percent increase in clock speed is more than satisfactory - results like these are impossible when using a conventional cooling system with a cooler and fan.

We used Quake 3 Arena and SETI as benchmarks, although the latter program was only run to ensure that we used virtually 100% of CPU capacity. Every CPU we tested was run at full capacity for several hours, which means that the overclocking rates listed here refer to rates in a stable PC system.

These charts clearly demonstrate that AMD processors that are factory-set to run faster hit the limits of their clock speed more rapidly than their slower siblings do - despite our effective water cooler.