The first time I heard of Cooler Master was when I ordered my first AMD processor and motherboard, for a deal I could get an aluminum Cooler Master Heatsink/Fan for a pretty good price. Six months later the fan stopped working, and I had to duct tape an 80mm fan on top of the heatsink so that my processor wouldn't fry. Regardless of the malfunction, the heatsink didn't perform very much better than a stock heatsink, and I was upset with not only the HSF, but also Cooler Master for what I believed to be poor design.
Less than a year ago I was offered the chance to review a case made by Cooler Master. I had read around and seen how other people praised Cooler Master's ATC series cases, so I gave it a shot. I was impressed to say the least, the cooling properties of the case were phenomenal, and the case not only looked good, it was a breeze to use.
Once again I was presented with a chance to review something from Cooler Master, a HSF for the Pentium 4. I was torn between my two experiences with Cooler Master products, but in the end I decided that the company had probably improved over time, and deserved a chance, and I was sent the Aero 4 cooler.
Seeing as this is the first aftermarket P4 cooler I've ever received, I was a bit surprised to say the least at the Aero 4's sheer size. It's massive. The heatsink is about the same size of the stock Pentium 4 cooler; with the fan mounted on the heatsink, it looks almost unruly.
The fan is surely the most visually outstanding feature of the heatsink. Instead of going with a traditional fan, Cooler Master has equipped the Aero 4 with a fan that best reminds me of a turbine. The "turbine" is powered by a DC ball bearing motor, and (as best as I can describe it,) is a one-ended cylinder with its height face cut up and angled into slices. When the fan starts spinning, the turbine slices will push the air present downwards, thereby drawing more air in.
I noticed that the fan could also be forced to turn by blowing air forcefully into the fan shroud's intake. Due to the positioning of the fan, the intake faces "down," instead of pointing away or towards the rear of the case. This only troubles me because if it were, the case fan could assist the heatsink fan by drawing in fresh air to the computer and also push the turbine faster. I tested the Aero 4 with the fan in both configurations.
The fan also has a potentiometer hooked up to it to reduce or increase fan speed. Potentiometers are voltage regulators, for more information you can google for potentiometer, or
Testing was done on a Chaintech 9CJS running a Pentium 4 2.4C, 1024MB Corsair XMS4000, ATI Radeon 9700, CoolerMaster ATC 220-B, Zalman 300W PSU. The comparison heatsink used was the Intel stock aluminum heatsink (without the copper core). Temperatures will be displayed in °C.
I found that the assumption made earlier, that the fan would be more effective if pushed by the case fan, and by also receiving cold air would be a better cooler was in fact incorrect. There were no noticeable temperature differences reported when the fan was turned.
I think I've grown to like the Aero 4 quite a bit. Although I thought the Potentiometer was going to be a waste, it ended up being quite useful. I found myself using it when I needed it, and the fan noise wasn't even that loud anyway.
Pros: Fan controller, good solid copper core
Cons: Sliding or swinging doors may hit potentiometer if mounted in 3.5" bay.
Bottom Line: Cooler Master has created a good high performance cooler that gives the user control and keeps the CPU cool enough for most users. If you got any comments, be sure to hit us up in our forums.