Introduction

Continuing our CPU cooler review series, this time we tested Mugen-2 from Scythe. It is a huge cooler, with five individual tower heatsinks, each one connected to the base by one U-shape copper heatpipe, with a 120 mm fan blowing air on them.

By the way, Mugen stands for "infinity" in Japanese.

The Mugen-2's box is big, but the impressive thing is the fact that when we open it, we notice the cooler is pratically the same size of the box, because there are no thick foam paddles that are used by some other coolers.

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Figure 1: Box.

Inside the box we found the cooler, the fan (not installed), user manual, installation hardware and a small bag of gray thermal compound.

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Figure 2: Box contents.

In Figure 3 we show the general look of Mugen-2. Let's see more details in next pages.

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Figure 3: Scythe Mugen-2.

Scythe Mugen-2

In a front view we notice the five practically independent heatsink design (they are united by some fins in order to give firmness to the piece). Scythe call this system M.A.P.S. (Multiple Airflow Pass-Through Structure).

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Figure 4: Front view.

Viewed from the side we can see that the cooler is very thick, with a big total fin area. Over the base you can see a small auxiliary heatsink.

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Figure 5: Side view.

In Figure 6 we have a top view of the cooler, and we have a better idea of this monster's size. There are mettalic nut-shaped caps in heatpipes tips, with aesthetics function only.

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Figure 6: Top view.

Scythe Mugen-2 (cont´d)

The 120 mm fan that accompanies Mugen-2 does not come installed. It is a simple black plastic model, without LEDs, but with PWM speed control as you can see in Figure 7. It must be attached to the heatsink using two wire clips.

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Figure 7: Fan.

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Figure 8: Fan installed.

The cooler base is nickel-plated copper and its finishing is perfectly mirrored.

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Figure 9: Base.

Installation

In Figure 10 we can see the hardware that comes with Mugen-2. The rubber-covered backplate that must be installed on the solder side of the motherboard is the same for any supported socket, but the mounting clips are different. The clips pair on the left is for use on the (obsolete) socket 478. Second one is for AMD CPUs (sockets AM3, AM2+, AM2, 939 and 754). The pair on the right is intended for use with Intel processors (sockets 775 and 1366). Socket 1156 is not supported by this cooler.

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Figure 10: Installation hardware.

In Figure 11, you can see the cooler base with the sockets 775 and 1366 clips installed.

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Figure 11: With socket 775 clips.

In order to install the cooler you must remove the motherboard from the case, unless it has a window on the motheboard tray to offer access to the solder side of the motherboard. After that, installation is easy, you must only put the screws on the backplate and fasten them to the cooler clips.

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Figure 12: Installed on the motherboard.

Figure 13 gives you an idea of Mugen-2's size inside the case. It is so big that we could not install our memory modules on the two first sockets of the motherboard, and we lose dual channel feature. But, with shorter memory modules, this installation could be possible. Another solution is to install the fan in another position, moving the face closer to the video card, for example.

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Figure 13: Installed into the case.

How We Tested

We are adopting the following methodology for our CPU cooler reviews.

First, we chose the CPU with the highest TDP (Thermal Design Power) we had available, a Core 2 Extreme QX6850, which has a 130 W TDP. The choice for a CPU with a high TDP is obvious. To measure the efficiency of the tested cooler, we need a processor that gets very hot. This CPU works by default at 3.0 GHz, but we overclocked it to 3.33 GHz, in order to heat it as much as possible.

We took noise and temperature measurements with the CPU idle and under full load. In order to achieve 100% CPU load on the four processing cores we ran Prime95 with the "In-place Large FFTs" option, and three instances of the StressCPU program, all at the same time.

We also compared the reviewed cooler to the Intel stock cooler (with copper base), which comes with the processor we used, and also with some other coolers we have tested using the same methodology.

Temperature measurements were taken with a digital thermometer, with the sensor touching the base of the cooler, and also with the core temperature reading (given by the CPU thermal sensor) from the from the SpeedFan program, using an arithmetic average of the four core temperature readings.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed 4" (10 cm) from the fan. We turned off the video board cooler so it wouldn't interfere with the results, but this measurement is only for comparative purposes, because a precise SPL measurement needs to be made inside an acoustically insulated room with no other noise sources, which is not the case here.

Hardware Configuration

• Processor: Core 2 Extreme QX6850
• Motherboard: Gigabyte EP45-UD3L
• Memory: 2 GB Corsair XMS2 DHX TWIN2X2048-6400C4DHX G (DDR2-800/PC2-6400 with timings 4-4-4-12), running at 800 MHz
• Hard drive: 500 GB Seagate Barracuda 7200.11 (ST3500320AS, SATA-300, 7200 rpm, 32 MB buffer)
• Video card: PNY Verto Geforce 9600 GT
• Video resolution: 1680x1050
• Video monitor: Samsung Syncmaster 2232BW Plus
• Power supply required: Seventeam ST-550P-AM
• Case: 3RSystem K100
  

Software Configuration

• Windows XP Professional installed on FAT32 partition
• Service Pack 3
• Intel Inf driver version: 8.3.1.1009
• NVIDIA video driver version: 182.08

Software Used

• Prime95
• StressCPU
• SpeedFan

Error Margin

We adopted a 2 ^oC error margin, i.e., temperature differences below 2 ^oC are considered irrelevant.

Our Tests

On the tables below you can see our results. We ran the same tests with the Intel stock cooler, Thermaltake BigTyp 14Pro, Akasa Nero, Cooler Master V10, Thermaltake TMG IA1, Zalman CNPS10X Extreme, Thermaltake ISGC-100, Noctua NH-U12P, Noctua NH-C12P, Thermaltake ISGC-200, Scythe Kabuto, Arctic Cooling Alpine 11 Pro, Thermaltake ISGC-300, SilverStone NT06-E, Zalman CNPS9700 NT and Scythe Mugen-2. Each test ran with the CPU idle and the with the CPU fully loaded. On BigTyp 14Pro, TMG IA1, NH-U12P and ISGC-300 the tests were done with the fan at full speed and at minimum speed. The other coolers were connected directly to the motherboard and it controls the fan speed based on CPU load level and temperature on PWM models.

On the graph below you can see the temperature difference between the cooler base and the room temperature with the CPU idle and fully loaded.  The values shown are in degrees Celsius. Remember that the lower the number the better the cooling performance.

The next graph will give you an idea on how many degrees Celsius the CPU core was hotter than room temperature during the tests.

Main Specifications

Scythe Mugen-2 main features are:

• Application: Socket 1366, 775, 478, AM3, AM2+, AM2, 939 and 754 processors.
• Fins: Aluminum.
• Base: Copper.
• Heat-pipes: Five copper heat-pipes.
• Fan: 120 mm.
• Nominal fan speed: 324 to 1,200 rpm.
• Fan air flow: 74.25 cfm.
• Maximum power consumption: 2.16 W.
• Nominal noise level: 26.5 dBA.
• Weight: 1.91 lbs (870 g).
• More information: http://www.scythe-usa.com
• Average price in the US*: USD 37.00

* Researched at Newegg.com on the day we published this review.