Test Results And Conclusion
We retain the hardware configuration from previous reviews to make all of our results comparable. Both the Gammaxx 400 and Noctua NH-U12S feature 120mm fans, while the Shadow Rock Slim puts a 135mm fan with 120mm hole spacing on a heat sink designed for 120mm fans.
Having never experienced superior cooling from direct-contact heat pipes, I've always thought these were a marketing ploy meant to excuse cheaper construction techniques. Might Deepcool's Gammaxx 400 be the first cooler to prove that notion incorrect?
The Gammaxx 400 produces incredibly good thermal results, though its more-powerful fan could be the key to those low temperatures. That fan also does a good job of cooling the CPU's PWM-based voltage controller.
Indeed, the fan produces more noise than competing models. Still, 31.2 decibels at full speed aren't so bad when used in a case with good noise isolation.
The Gammaxx 400 has a worse noise-to-cooling ratio than the Shadow Rock Slim at full speed, but a better cooling-to-noise ratio when cranked down to 50 percent duty cycle. Duty Cycle is an important concept because the fan controller is also PWM-based.
The Gammaxx 400 might trade blows with the Shadow Rock Slim in cooling-to-noise ratio, but comparing that performance metric to price allows Deepcool to drive home the value message. At a mere $30, it's far cheaper than the Shadow Rock Slim and less than half the price of the NH-U12S.
How could it be so much cheaper? To begin with, Deepcool doesn't have the "window dressing" of a finished top plate with aluminum caps over the tips of its heat pipes. We can also be relatively certain that the fan bearings won't last as long, since Deepcool warranties the unit for a mere two years. Yet at this price difference, we could replace the fan twice and still find at least equal value to the Shadow Rock Slim.
The superb price for Deepcool's Gammaxx 400 puts this editor in a difficult position, since the performance is only on par with the Shadow Rock Slim. If I were building a machine to show off, I'd certainly pay a little more for that pretty top cap. But who am I kidding? I don't actually pay for computer parts unless I'm building for the System Builder Marathon. And then I'm paying with someone else's money.
Keeping in mind that the System Builder Marathon always ends in a value competition, Deepcool's $30 Gammaxx 400 is the cooler I'd choose for value. In fact, I plan to use one in my next build. It might not be the cooler I'd always choose, but it is the one I'd choose most often, and that makes it the first low-cost part to earn the respect of an Editor's Choice award.