The best way to test a heatsink is too see how low it can bring the CPU's temperature.  To do this test we used Soyo's SY-6BA+IV motherboard which directly reads the temperature sensor within the processors core.  This is the most accurate way to get a CPU's temperature reading.  We used Motherboard Monitor to read the temperature from within Windows 98.  We recorded both case and CPU temperatures under an idle state and a heavy load state (right after exciting Unreal Tournament).  Note, the system/CPU temperatures may vary from your own tests because of different hardware/cooling configurations.  My case has two 80mm chassis fans and a hard drive cooler along with a full array of expansion cards and 2 hard drives which may affect the results.

**Note** A thin layer of MPU 3.7 thermal grease was used on all the heatsinks to ensure maximum heat transfer.

Here is the system configuration used for this test:

All of the cooler were able to sustain my Celeron 400 at 540MHz (6 x 90 MHz FSB).  So as a basis of comparison, I tested each of the heatsinks/fans at this speed.  The temperature readings are in Degrees Celsius.

That new ALPHA PAL6035 really kicks ass!  That copper insert really makes a difference.  Notice the case temperature using this ALPHA cooler, it's 1-2 degrees higher than what it is with the other coolers, that means it's doing a good job at throwing the processor's heat into the air and keeping it off.  The FDP32 and the ALPHA PFH6035 duke it out for second place with the FDP32 only slightly edging it out.  As you can see, the Peltier just plain sucked, almost causing the CPU to overheat.  Even the small Vantec heatsink beat the Vantec Peltier cooler by a significant amount.

Please note that you're results may vary.  How far you can overclock highly depends on the quality of your processor and how much extra cooling you have in your system. 

Passed - means, complete stability for days.  Sometimes a processor appears stable, but after a few days you start to notice problems.

Failed - means it either doesn't fully boot into Windows, or it boots and runs for a while, but crashes quickly or locks up.  Unacceptable.

A percentage indicates that the system is stable that percentage of the time, with minor cases of instability (such as an abnormal crash occasionally).

What can I say? ALPHA is once again the king.  With their new PAL6035 for Socket 7/370 and the PEP66U for FC-PGA Coppermine CPU's, you've got the best conventional cooling solutions around.  You get an awesomely built heatsink that performs great and looks great (in case you have a transparent case or just care about how things look :)  The only downside, is the slightly higher price.  The FDP32 provides great cooling power at a very low price, but is monstrously large and may not fit well with your motherboard, especially if you use a Socket-370 to Slot-1 converter card.

The ALPHA PAL6035 gets our gold editors choice award and the FDP32 gets the silver editor's choice award!

Alpha PAL6035

Global WIN FDP32

If you would like to order any of these coolers, head over to the CoolerGuys.