Bulky, but it gets the job done

They just keep getting bigger and bigger. Now that CPU air-cooling manufacturers have seemingly settled on the skyscraper school of heatsink design, there seems to be a competition over who can cram the most cooling fins into the largest area. Scythe’s Mugen 2 air cooler, the follow-up to its popular Mugen series, is one of the largest coolers of this type that we’ve ever tested. But can it match the cooling power of its slightly smaller cousins, such as Thermalright’s U-120 eXtreme?

The Mugen 2 is a hefty hunk of a cooler, at 5.1 inches wide, 5 inches deep (with the included 12cm fan), and 6.2 inches high; it weighs nearly two pounds. It’s not the heaviest cooler we’ve ever tested, nor the most unwieldy, but its girth could certainly prevent you from installing it in all orientations on all motherboards. We had trouble fitting it in some orientations on our EVGA 680i SLI board—our usual preference being to install the cooler fan parallel with the rear exhaust fan. On our board, though, there wasn’t room; we resorted to attaching the cooler fan perpendicular to the rear exhaust fan. Thankfully, this didn’t seem to impact performance, as the Mugen 2 performed slightly better in our tests than the Thermalright U120-eXtreme—about 2.25 C cooler at both idle and full CPU burn.

The Mugen 2 pushes the upper limit on air-cooler size, but we'll allow it. This time.

The Mugen 2 ships with mounting brackets for LGA1366, 775, and AMD boards; the first two use the same bracket and backplate but different screw holes. Support for the new LGA1156 socket wasn’t available at the time of this review, but the company states it is in the works. Installation requires motherboard removal or a motherboard tray with a backplane cutout. Each of its five copper heat pipes rises into its own separate stack of cooling fins, allowing airflow between the stacks.

If you opt to use the included 12cm fan, you might have to tweak your motherboard fan control settings due to its four-pin PWM connector. We manually set the fan control to 100 percent for testing, after the motherboard’s fan control resulted in significantly higher temperatures.

You can attach up to four 12cm fans to the Mugen 2—one to each face of the fin array—using the familiar thin wire clips found on similar coolers. Whether this actually helps, of course, is up for debate. We didn’t see any performance gains when we experimented with multiple fans on the Noctua NH-U12P and Thermalright U-120 eXtreme.

For laudable performance, a relatively easy install compared to its peers, and a lower price point, we’re awarding the Scythe Mugen 2 our Kick Ass Award. However, this is clearly the upper limit of how big a cooler can be and still earn a high recommendation. Hear that, vendors? Scale ‘em down a bit.

Scythe Mugen 2

Mugison

Kick-ass cooling at a kick-ass price. Relatively easy installation for a cooler of this type.

Murgatroyd

Manual mode gets best results; massive.

Scythe

Benchmarks

	Scythe Mugen 2	Thermalright U120-eXtreme	Stock Cooler
Idle (C)	27.75	29.75	33.75
100% Burn (C)	43	45.25	61

Best scores are bolded. Idle temperatures were measured after an hour of inactivity; load temperatures were measured after an hour's worth of CPU Burn-in (four instances). Test system consists of a stock-clock Q6700 processor on an EVGA 680i motherboard inside a Cooler Master ATCS 840 case with stock fans.