To give you an idea of how each cooler performs in an overclocked environment, our processor FSB was increased to 250MHz and the voltage on the processor core increased to 1.700 volts which is an 0.175 volt increase over the default voltage setting of the Pentium 4 Northwood core - it will be interesting to see how the coolers handle the higher voltage and how it reflects in our tests.
At 250MHz FSB or 3500MHz clock, with the stock Intel HSF our test system became unstable. We were able to move up to 265MHz FSB or 3710MHz clock before we started seeing system instability with the Corsair HydroCool 200. Due to the high FSB, we are getting to the point where the stock northbridge cooler on the IC-7 is becoming our limitation due to the heat the northbridge is putting out - not necessarily the Corsair HydroCool 200.
Idle Temperature - 250 FSB
Overclocked idle temperatures show a huge 12.5c or roughly a 34% difference between the two coolers.
Load Temperature - 250 FSB
Under load the gap is closer but the stock HSF is almost touching 60c while the HydroCool is at 50c which is 19% cooler than the stock HSF and much more workable if you intend on hitting these highly overclocked speeds yourself.