Introduction

The Dark Rock 2 is a CPU cooler from be quiet! with a tower heatsink, one 135 mm fan, and six heatpipes. Let’s test it and see if the company’s name truly reflects this product’s operation.

The black box of the Dark Rock 2 is shown in Figure 1.

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Figure 1: Package

Figure 2 shows the contents of the box: the cooler itself, a small syringe of thermal compound, manual, and installation hardware.

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Figure 2: Accessories

Figure 3 displays the Dark Rock 2.

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Figure 3: The Dark Rock 2

This cooler is discussed in detail in the following pages.

The be quiet! Dark Rock 2

Figure 4 illustrates the front of the cooler, which is covered by the 135 mm fan. Notice that the blades of the fan are not plain; they have ripples that help minimize the turbulence and, thus, the noise.

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Figure 4: Front view

Figure 5 reveals the side of the cooler.

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Figure 5: Side view

Figure 6 shows the rear of the cooler. The edges of the fins are straight, creating a flat surface.

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Figure 6: Rear view

In Figure 7, you can see the top of the cooler.

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Figure 7: Top view

The be quiet! Dark Rock 2 (Cont’d)

The six 6 mm nickel-plated copper heatpipes are visible in Figure 8. They are disposed in two rows inside each side of the heatsink.

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Figure 8: Heatpipes

Figure 9 illustrates the base of the cooler. It is a nickel-plated copper plate with mirror-like finishing.

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Figure 9: Base

Figure 10 reveals the Dark Rock 2 without the fan. The fins create a concave surface.

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Figure 10: Without the fan

Figure 11 shows the 135 mm PWM fan that comes with the cooler, with the wire holders.

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Figure 11: Fan

Installation

Figure 12 shows the backplate for installing the Dark Rock 2 on all compatible CPUs, except LGA2011 systems, which don’t require a backplate.

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Figure 12: Backplate

Figure 12 shows the pair of holders for sockets 1155/1156 installed at the base of the cooler. There are three additional pairs of holders: one for socket LGA2011, one for sockets 775 and 1366, and one for all AMD processors.

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Figure 13: Holders installed

The installation is simple: just put the cooler in place and fasten the four screws from the solder side of the motherboard.

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Figure 14: Cooler installed

How We Tested

We tested the cooler with a Core i5-2500K CPU (quad-core, 3.3 GHz), which is a socket LGA1155 processor with a 95 W TDP (Thermal Design Power). In order to get higher thermal dissipation, we overclocked it to 4.0 GHz (100 MHz base clock and x40 multiplier), with 1.3 V core voltage (Vcore). This CPU was able to reach 4.8 GHz with its default core voltage, but at this setting, the processor enters thermal throttling when using mainstream coolers, reducing the clock and thus the thermal dissipation. This could interfere with the temperature readings, so we chose to maintain a moderate overclocking.

We measured noise and temperature with the CPU under full load. In order to get 100% CPU usage in all cores, we ran Prime 95 25.11 with the “In-place Large FFTs” option. (In this version, the software uses all available threads.)

We compared the tested cooler to other coolers we already tested, and to the stock cooler that comes with the Core i5-2500K CPU. Note that the results cannot be compared to measures taken on a different hardware configuration, so we retested some “old” coolers with this new methodology. This means you can find different values in older reviews than the values you will read on the next page. Every cooler was tested with the thermal compound that comes with it.

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings.

During the tests, the panels of the computer case were closed. The front and rear case fans were spinning at minimum speed in order to simulate the “normal” cooler use on a well-ventilated case. We assume that is the common setup used by a cooling enthusiast or overclocker.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed near the top opening of the case. This measurement is only for comparison 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 i5-2500K
• Motherboard: ASUS Maximus IV Extreme-Z
• Memory: 6 GB OCZ (DDR3-1600/PC3-12800), configured at 1,600 MHz and 8-8-8-18 timings
• Hard disk: Seagate Barracuda XT 2 TB
• Video card: Point of View GeForce GTX 460 1 GB
• Video resolution: 1920x1080
• Video monitor: Samsung SyncMaster P2470HN
• Power supply: Seventeam ST-550P-AM
• Case:  Cooler Master HAF 922

Operating System Configuration

• Windows 7 Home Premium 64 bit SP1

Software Used

• Prime95
• SpeedFan

Error Margin

We adopted a 2°C error margin, meaning temperature differences below 2°C are considered irrelevant.

Our Tests

The table below presents the results of our measurements. We repeated the same test on all coolers listed below. Each measurement was taken with the CPU at full load. In the models with a fan supporting PWM, the motherboard controlled the fan speed according to core load and temperature. On coolers with an integrated fan controller, the fan was set at the full speed.

Cooler	Room Temp.	Noise	Speed	Core Temp.	Temp. Diff.
Cooler Master Hyper TX3	18 °C	50 dBA	2850 rpm	69 °C	51 °C
Corsair A70	23 °C	51 dBA	2000 rpm	66 °C	43 °C
Corsair H100	26 °C	62 dBA	2000 rpm	64 °C	38 °C
EVGA Superclock	26 °C	57 dBA	2550 rpm	67 °C	41 °C
NZXT HAVIK 140	20 °C	46 dBA	1250 rpm	65 °C	45 °C
Thermalright True Spirit 120	26 °C	42 dBA	1500 rpm	82 °C	56 °C
Zalman CNPS12X	26 °C	43 dBA	1200 rpm	71 °C	45 °C
Zalman CNPS9900 Max	20 °C	51 dBA	1700 rpm	62 °C	42 °C
Titan Fenrir Siberia Edition	22 °C	50 dBA	2400 rpm	65 °C	43 °C
SilenX EFZ-120HA5	18 °C	44 dBA	1500 rpm	70 °C	52 °C
Noctua NH-L12	20 °C	44 dBA	1450 rpm	70 °C	50 °C
Zalman CNPS8900 Extreme	21 °C	53 dBA	2550 rpm	71 °C	50 °C
Gamer Storm Assassin	15 °C	48 dBA	1450 rpm	58 °C	43 °C
Deepcool Gammaxx 400	15 °C	44 dBA	1500 rpm	60 °C	45 °C
Cooler Master TPC 812	23 °C	51 dBA	2350 rpm	66 °C	43 °C
Deepcool Gammaxx 300	18 °C	43 dBA	1650 rpm	74 °C	56 °C
Intel stock cooler	18 °C	41 dBA	2000 rpm	97 °C	79 °C
Xigmatek Praeton	19 °C	52 dBA	2900 rpm	83 °C	64 °C
Noctua NH-U12P SE2	18 °C	42 dBA	1300 rpm	69 °C	51 °C
Deepcool Frostwin	24 °C	46 dBA	1650 rpm	78 °C	54 °C
Thermaltake Frio Advanced	13 °C	56 dBA	2000 rpm	62 °C	49 °C
Xigmatek Dark Knight Night Hawk Edition	9 °C	48 dBA	2100 rpm	53 °C	44 °C
Thermaltake Frio Extreme	21 °C	53 dBA	1750 rpm	59 °C	38 °C
Noctua NH-U9B SE2	12 °C	44 dBA	1700 rpm	64 °C	52 °C
Thermaltake WATER2.0 Pro	15 °C	54 dBA	2000 rpm	52 °C	37 °C
Deepcool Fiend Shark	18 °C	45 dBA	1500 rpm	74 °C	56 °C
Arctic Freezer i30	13 °C	42 dBA	1350 rpm	63 °C	50 °C
Spire TME III	8 °C	46 dBA	1700 rpm	70 °C	62 °C
Thermaltake WATER2.0 Performer	11 °C	54 dBA	2000 rpm	49 °C	38 °C
Arctic Alpine 11 PLUS	11 °C	45 dBA	2000 rpm	82 °C	71 °C
be quiet! Dark Rock 2	10 °C	41 dBA	1300 rpm	58 °C	48 °C

In the graph below, you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the cooler.

In the graph below, you can see how many decibels of noise each cooler makes.

Main Specifications

The main specifications for the be quiet! Dark Rock 2 CPU cooler include:

• Application: Sockets 775, 1155, 1156, 1366, 2011, AM2(+), AM3(+), and FM1 processors
• Dimensions: 5.4 x 3.1 x 6.5 inches (138 x 97 x 166 mm) (W x L x H)
• Maximum TDP: 180 W
• Fins: Aluminum
• Base: Nickel-plated copper
• Heat-pipes: Six 6-mm nickel-plated copper heatpipes
• Fan: 135 mm
• Nominal fan speed: 1,300 rpm
• Fan air flow: 57.9 cfm
• Power consumption: 2.64 W
• Nominal noise level: 21.2 dBA
• Weight: 1.9 lbs (860 g)
• More information: http://www.bequiet.com
• MSRP in the U.S.: USD 77.00

Conclusions

Our tests proved that the name of the manufacturer is in accordance with the product: the Dark Rock 2 is really quiet. It is actually the most silent high-performance CPU cooler that we tested so far.

Although the be quiet! Dark Rock 2 doesn’t have the same performance level as the top performers we tested to date, it reached a better performance level than the other “extra silent” coolers to which we are comparing it.

If you are looking for a really quiet, nice looking, and good-performance CPU cooler, the be quiet! Dark Rock 2 is a sure bet. That’s why it receives the Hardware Secrets Golden Award.