The be quiet! Dark Rock 2 is a big tower CPU cooler with an odd 135 mm fan. Unfortunately, our sample has trouble living up to its German manufacturer’s name. Note: Addendum on final page (8), 1 Aug 2012.
July 20, 2012 by Lawrence Lee
Product | be quiet! Dark Rock 2 CPU Cooler |
Manufacturer | be quiet! |
Street Price | £50 inc. VAT |
Given our purview, we take a keen interest in PC components that are marketed as “quiet” or “silent.” Sometimes we exercise a little extra scrutiny on products that include the words in the name. When a manufacturer goes one step further and calls themselves something like be quiet! it perks our interest even more as it implies that everything they make has been and will be designed with noise reduction in mind.
be quiet! is a German company that produces power supplies and cooling solutions for desktop PCs. According to their website, “be quiet! sticks to its name: More than ten years experience in the field of noise reduction and silence make be quiet! products probably the most silent one on the market.” It’s an ambitious claim that we’ll gladly put to the test.
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be quiet! makes their CPU cooler debut at SPCR with the Dark Rock 2, yet another tower heatsink. The box claims it has the proficiency to handle an 180W TDP processor and they also made a point to advertise LGA2011 support. It’s a non too subtle implication that it’s suitable for a heavily overclocked Sandy Bridge Extreme. The heatsink is equipped with one of their signature SilentWings fan, which has a fairly unusual design.
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The heatsink is packed in foam while a small accessory box holds the manual, thermal compound, and mounting hardware. The kit supports all of Intel and AMD’s modern desktop sockets and includes a backplate, essentially mandatory for a cooler of this size. The mounting procedure requires the bolts to enter through the back, so the motherboard has to be turned upside-down to facilitate installation. The only way you can mount this heatsink with the motherboard already bolted in the case is if there is a large opening on the motherboard tray giving access to the underside of the board.
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The heatsink itself doesn’t have a remarkable design, a six heatpipe tower resembling various offerings from many other manufacturers. The entire body is nickel-plated, a popular feature that gives heatsinks a menacing luster. The fan is very distinctive with ridged blades and oddly placed mounting holes (they stick out at the center rather being flush either either edge). It’s also a weird size, 135 mm (137 mm by our measurements).
be quiet! Dark Rock 2: Key Features (from the product web page) | |
Feature & Brief | Our Comment |
Very quiet operation 135mm SilentWings® fan with PWM function for optimized fan speed throughout the entire working range provides the perfect balance between superior cooling and quiet. The specially developed wave shaped contour of the heatsink fins optimizes airflow and avoids noise generating turbulence. | Many manufacturers create a non-uniform surface for the fan to press against, but in our experience, it makes no difference, at least not at low fan speed levels. |
Highly effective cooling Six ultra-high performance heatpipes with an oxygen-free copper layer help to transport the heat directly to the optimal place of the heatsinks. | Standard for high performance heatsinks. |
First-class materials Dark nickel-plated metal surfaces and a solid brushed aluminum cover. A stable backplate ensures secure attachment, even when the computer is being transported. | Nickel-plating gives it a nice sheen and prevents oxidation. Backplates are a necessity for heavy coolers. |
Product conception, design and quality control in Germany 3 years warranty | Nice, but how often to heatsinks become faulty? |
be quiet! Dark Rock 2 Rev.A: Specifications (from the product web page) | |
Overall dimensions without mounting material (L x W x H) (mm) | 97 x 138 x 166 |
Total weight (kg) | 0.86 |
TDP (W) | 180 |
LGA2011 | Yes |
Socket compatibility | Intel: LGA 775 / LGA 1155 / LGA 1156 / LGA 1366 / LGA 2011 AMD: FM1, AM2 (+) / AM3 (+) / 754/ 939 / 940 |
Backplate Mounting | Yes |
Anti vibration fan fixing | – |
Overall noise level (dB(A)) @ 900/1250/100% (rpm) | 8.7 / 13.9 / 21.2 |
Heatsink | |
Number of fins | 44 |
Fin material | Aluminum |
Base material | Copper |
CPU contact surface | CNC machined |
Heatpipe number, Diameter (mm) | Heatpipe number, Diameter (mm) 6x 6 |
Surface treatment | Aluminum / Dark nickel-plated |
Fan | |
Fan dimensions (mm) | 135 x 135 x 25 |
SilentWings | Yes |
Speed @ 100% PWM (rpm) | 1300 |
Air flow @ 12V (cfm, m3/h) | 57.9 ; 96.8 |
Air pressure @ 12V (mm H2O) | 1.64 |
Bearing type | Fluid Dynamic Bearing |
Rated voltage (V) | 12 |
Input current (A) | 0.25 |
Input power (W) | 2.64 |
Connector | 4-pin PWM |
Cable length (mm) | 200 |
Lifespan (h / 25°C) | 300,000 |
PHYSICAL DETAILS & INSTALLATION
The be quiet! Dark Rock 2 is composed of a copper base, 6 x 6 mm thick copper heatpipes friction-fit to to 44 aluminum fins, all nickel-plated. The heatsink measures 165 mm tall, but the effective height may be greater depending on how high the fan is mounted. According to our digital scale, It weighs approximately 890 grams or 720 grams without the fan and clips.
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BASE & INSTALLATION
The most critical aspect of installation is that the heatsink be securely
mounted. A firm mating results in good contact between the heatsink’s base and
the CPU heatspreader and more efficient heat conduction. Ideally it should
also be a simple procedure with the user having to handle as few pieces of
hardware as possible.
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TESTING
Before thermal testing, we took some basic physical measurements.
Approximate Physical Measurements | |
Weight | 720 g 890 g with stock fan and clips |
Height | 165 mm |
Fin count | 44 |
Fin thickness | 0.38 mm |
Fin spacing | 2.22 mm |
Vertical Clearance* | 51 mm |
* measured from the motherboard PCB to the bottom fin of the heatsink |
Large Heatsink Comparison: Average Fin Thickness & Spacing | ||
Heatsink | Fin Thickness | Fin Spacing |
Thermalright HR-01 Plus | 0.45 mm | 3.15 mm |
Scythe Ninja 3 | 0.39 mm | 2.64 mm |
Noctua NH-U12P | 0.44 mm | 2.63 mm |
Noctua NH-C12P | 0.47 mm | 2.54 mm |
Noctua NH-D14 | 0.43 mm | 2.33 mm |
Thermalright Archon SB-E | 0.49 mm | 2.33 mm |
be quiet! Dark Rock 2 | 0.38 mm | 2.22 mm |
Prolimatech Armageddon | 0.51 mm | 2.08 mm |
Prolimatech Megahalems | 0.50 mm | 2.00 mm |
Zalman CNPS10X Quiet | 0.40 mm | 2.00 mm |
Scythe Kabuto & Zipang 2 | 0.34 mm | 1.94 mm |
NZXT Havik 140 | 0.41 mm | 1.91 mm |
Scythe Mugen-2 | 0.31 mm | 1.89 mm |
Swiftech Polaris 120 | 0.43 mm | 1.85 mm |
Thermalright Venomous X | 0.53 mm | 1.84 mm |
Noctua NH-C14 | 0.38 mm | 1.79 mm |
Scythe Yasya | 0.32 mm | 1.78 mm |
Cogage TRUE Spirit 1366 | 0.40 mm | 1.70 mm |
Arctic Cooling Freezer Xtreme Rev.2 | 0.30 mm | 1.70 mm |
Scythe Grand Kama Cross | 0.38 mm | 1.66 mm |
Reeven Kelveros | 0.47 mm | 1.61 mm |
Zalman CNPS9900 MAX | 0.16 mm | 1.59 mm |
Thermalright Silver Arrow | 0.32 mm | 1.57 mm |
Cooler Master Hyper 212 Plus | 0.43 mm | 1.54 mm |
Thermalright Ultra-120 eXtreme Rev.C | 0.56 mm | 1.52 mm |
Zalman CNPS10X Extreme | 0.42 mm | 1.50 mm |
Testing on larger heatsinks are done on our
LGA1366 heatsink testing platform, while smaller coolers tackle our LGA1155 heatsink testing platform. A summary of the test system
and procedure follows.
Key Components in LGA1366 Heatsink Test Platform:
- Intel Core i7-965 Extreme
Nehalem core, LGA1366, 3.2GHz, 45nm, 130W TDP. - Asus
P6X58D Premium ATX motherboard. X58 chipset. - Asus
EAH3450 Silent graphics card. - Intel
X25-M 80GB 2.5″ solid-state drive. Chosen for silence. - 3GB QiMonda
DDR3 memory. 3 x 1GB DDR3-1066 in triple channel. - Seasonic X-650 SS-650KM
650W ATX power supply. This PSU is semi-passively cooled. At the power levels
of our test platform, its fan does not spin. - Arctic Silver
Lumière: Special fast-curing thermal interface material, designed
specifically for test labs. - Noctua 140 mm fan (used when possible with heatsinks that fit 140x25mm
fans) - Nexus 120 mm fan (used when possible with heatsinks that fit 120x25mm
fans) - Nexus 92 mm fan (used when possible with heatsinks that fit 92x25mm
fans)
The systems are silent under the test conditions, except for the CPU cooling
fan(s).
Normally, our reference fans are used whenever possible, the measured details
of which are shown below.
Reference Noctua 140mm fan Anechoic chamber measurements | ||
Voltage | SPL@1m | Speed |
12V | 28~29 dBA | 1250 RPM |
9V | 21 dBA | 990 RPM |
7V | 15~16 dBA | 770 RPM |
6V | 13 dBA | 660 RPM |
Reference Nexus 120mm fan Anechoic chamber measurements | ||
Voltage | SPL@1m | Speed |
12V | 16 dBA | 1100 RPM |
9V | 13 dBA | 890 RPM |
7V | 12 dBA | 720 RPM |
Reference Nexus 92 mm fan Anechoic chamber measurements | ||
Voltage | SPL@1m | Speed |
12V | 16 dBA | 1470 RPM |
9V | 12 dBA | 1150 RPM |
Measurement and Analysis Tools
- Extech 380803 AC power analyzer / data logger for measuring AC system
power. - Custom-built, four-channel variable DC power supply, used to regulate
the fan speed during the test. - PC-based spectrum analyzer:
SpectraPlus with ACO Pacific mic and M-Audio digital
audio interfaces. - Anechoic chamber
with ambient level of 11 dBA or lower - Various other tools for testing fans, as documented in our
standard fan testing methodology. - SpeedFan,
used to monitor the on-chip thermal sensors. The sensors are not calibrated,
so results are not universally applicable. The hottest core reading is used. - Prime95,
used to stress the LGA1366 CPU heavily, generating more heat than most real applications.
8 instances are used to ensure that all 4 cores (with Hyper-threading) are
stressed. - CPU-Z,used to monitor the CPU speed to determine when overheating occurs.
- Thermometers to measure the air temperature around the test platform
and near the intake of the heatsink fan.
Noise measurements are made with the fans powered from the lab’s variable DC
power supply while the rest of the system was off to ensure that system noise
did not skew the measurements.
Load testing was accomplished using Prime95 or CPUBurn to stress the processor, and the
graph function in SpeedFan was used to ensure that the load temperature is stable
for at least ten minutes. The temperature recorded is the highest single core
reading. The stock fans were tested at various voltages to represent a good
cross-section of airflow and noise performance.
The ambient conditions during testing were 10~11 dBA and 21~23°C.
STOCK FAN MEASUREMENTS
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Specifications: be quiet! Dark Rock 2 | |||
Manufacturer | Power Rating | 3.0 W | |
Model Number | BQT T13525-MF-PWM | Airflow Rating | 57.9CFM |
Bearing Type | ? | Speed Rating | 1,300 RPM |
Corners | Open | Noise Rating | 21.2 dBA |
Frame Size | 137 x 137 x 25 mm | Header Type | 4-pin |
Fan Blade Diameter | 128 mm | Starting Voltage | < 5.0 V |
Hub Size | 47 mm | Weight | 170 grams |
Data in green cells provided by the manufacturer or observed; data in the blue cells were measured. |
The Dark Rock 2’s stock fan has a very interesting design. It’s slightly smaller than a 140 mm model, its blades have ridges, and the circular frame has a soft, rubberized rim, possibly for dampening. The hub is unusually large, measuring 47 mm across; most 140 mm fans have a hub diameter of ~40 mm. The cable is short, measuring only 20 cm.
Stock Fan Measurements | ||
Voltage | Speed | SPL@1m |
12V | 1280 RPM | 24 dBA |
10V | 1020 RPM | 19 dBA |
9V | 770 RPM | 15 dBA |
8.5V | 630 RPM | 13 dBA |
8V | 480 RPM | 12 dBA |
7V | 350 RPM | <11 dBA |
Measuring mic positioned 1m at diagonal angle from the center of the heatsink. Ambient noise level: 10~11 dBA. |
The stock fan is more finely controlled when PWM is used; with voltage control, the stock fan is only audible above 7V. Its motor produces a low pitched hum that increases in intensity almost proportionally with the fan speed. It’s not particularly pleasant, but it’s consistent, not developing any odd tones or quirks at different speed levels. At higher fan speeds, it generates more turbulent noise but this is true of all fans.
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The fan has some tonal elements, particularly at ~350 Hz.
TEST RESULTS
be quiet! Dark Rock 2 | |||
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Fan Voltage | SPL@1m | Temp | °C Rise |
Stock Fan | |||
12V | 24 dBA | 66°C | 46 |
10V | 19 dBA | 68°C | 48 |
9V | 15 dBA | 72°C | 52 |
8.5V | 13 dBA | 75°C | 55 |
8V | 12 dBA | 81°C | 61 |
Reference Noctua 140mm Fan | |||
12V | 28 dBA | 66°C | 46 |
9V | 21 dBA | 69°C | 49 |
7V | 15 dBA | 71°C | 51 |
6V | 12~13 dBA | 73°C | 53 |
Reference Nexus 120mm Fan | |||
12V | 15 dBA | 68°C | 48 |
9V | 13 dBA | 70°C | 50 |
7V | 11~12 dBA | 72°C | 52 |
°C Rise: Temperature rise above ambient (20°C) at load. |
The Dark Rock 2’s cooling proficiency is not great for a heatsink of its size. The better coolers we’ve tested over the years typically do not exceed a thermal rise above ambient of 50°C on our test platform, even at close to inaudible noise levels. The Dark Rock 2, with its stock fan at 8V measuring just 12 dBA@1m, exceeded 60°C above ambient, and the result at full speed was only 46°C.
Though the Dark Rock 2 doesn’t have a mounting option for a standard 120/140 mm fan, we Jerry-rigged both our reference Noctua 140 mm and Nexus 120 mm fan to it anyway, to see if the stock fan was part of the reason for its poor performance. CPU cooling was fairly similar with the Noctua, except for a significant improvement at the 12~13 dBA@1m level. The smaller Nexus fan performed noticeably better (as it tends to do) but not enough to save the heatsink from being classified as subpar.
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Disappointed by the results, we checked the thermal compound footprint after testing and discovered the heatsink wasn’t making very good contact with the processor, indicated by the noticeable “branching” pattern that was produced. There was also more excess TIM on the sides due to the base’s uneven surface which we mentioned earlier.
In attempt to create more pressure, we re-tested the heatsink without the plastic spacers that were placed between the mounting clips and the motherboard PCB but the results were the same.
Heatsink Comparison Table
CPU Coolers (ref. 140mm fan): °C Rise Comparison | |||
Heatsink | Fan voltage / SPL @1m* | ||
9V | 7V | 6V | |
18~21 dBA | 13~16 dBA | 11~13 dBA | |
Thermalright Archon SB-E | 37 | 40 | 42 |
Prolimatech Armageddon | 39 | 42 | 45 |
Thermalright Venomous X Silent Edition | 40 | 43 | 44 |
NZXT Havik 140 | 40 | 43 | 47 |
Noctua NH-C14 (top mounted) | 40 | 44 | 48 |
Noctua NH-C14 | 40 | 44 | 49 |
Thermalright Silver Arrow | 39 | 45 | 49 |
be quiet! Dark Rock 2 | 49 | 51 | 53 |
*Note: there are minor differences in measured SPL due to the variety of fan orientations and mounting methods offered by the compared coolers. |
When using our reference 140 mm fan, the Dark Rock 2 sinks like a rock, ending up at the bottom of our chart, trailing the leading Thermalright Archon SB-E by more than 10°C.
CPU Coolers (ref. 120mm fan): °C Rise Comparison | |||
Heatsink | Fan voltage / SPL @1m* | ||
12V | 9V | 7V | |
15~16 dBA | 12~13 dBA | 11~12 dBA | |
Thermalright Ultra-120 eXtreme Rev.C | 38 | 40 | 43 |
Thermalright Venomous X | 38 | 41 | 43 |
Prolimatech Megahalems | 38 | 41 | 44 |
Noctua NH-U12P | 39 | 42 | 44 |
Scythe Mugen-2 | 39 | 42 | 45 |
Cogage TRUE Spirit 1366 | 40 | 42 | 45 |
Prolimatech Armageddon | 40 | 42 | 46 |
Zalman CNPS10X Quiet | 40 | 43 | 46 |
Noctua NH-C14 | 39 | 42 | 48 |
Scythe Yasya | 41 | 43 | 47 |
Thermalright Ultra-120 eXtreme | 40 | 43 | 48 |
Cooler Master Hyper 212 Plus | 41 | 44 | 48 |
Thermalright Archon SB-E | 42 | 43 | 49 |
Thermalright Ultra-120 | 42 | 45 | 49 |
Titan Fenrir | 43 | 46 | 50 |
Scythe Ninja 3 | 44 | 47 | 49 |
Noctua NH-C12P | 43 | 47 | 51 |
Zalman CNPS10X Extreme | 43 | 47 | 53 |
Swiftech Polaris 120 | 46 | 49 | 54 |
Zalman CNPS10X Flex | 45 | 50 | 54 |
be quiet! Dark Rock 2 | 48 | 50 | 52 |
Cooler Master V8 | 46 | 50 | 54 |
Reeven Kelveros | 47 | 51 | 55 |
Scythe Grand Kama Cross | 45 | 52 | 57 |
Antec Kühler H20 620 (pump at 7V, almost inaudible) | 52 | 52 | 53 |
Arctic Cooling Freezer Xtreme Rev.2 | 49 | 52 | 58 |
Scythe Kabuto | 51 | 53 | 60 |
*Note: there are minor differences in measured SPL due to the variety of fan orientations and mounting methods offered by the compared coolers. |
Unfortunately for be quiet!, our Nexus 120 mm fan results gives us more perspective. We’ve only encountered one traditional tower heatsink with worse performance, the Reeven Kelveros.
MP3 SOUND RECORDINGS
These recordings were made with a high
resolution, lab quality, digital recording system inside SPCR’s
own 11 dBA ambient anechoic chamber, then converted to LAME 128kbps
encoded MP3s. We’ve listened long and hard to ensure there is no audible degradation
from the original WAV files to these MP3s. They represent a quick snapshot of
what we heard during the review.
These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!
The recording starts with 5~10 second segments of room ambiance, then the fan
at various levels. For the most realistic results, set the volume so that
the starting ambient level is just barely audible, then don’t change the volume
setting again.
- be quiet! Dark Rock 2 with stock fan at 1m
— 9V (15 dBA@1m)
— 10V (19 dBA@1m)
— 12 (24 dBA@1m)
TESTING REDUX – by Mike Chin be quiet! was shown a preview of this review a week ago, and their reaction was that we should have notified them immediately about such sub-par results. They’d received positive reviews from several other hardware sites, and were certain that our results were due to a substandard sample that managed to slip by their QA. So, we decided to give them a second chance, and they express-shipped over two more samples of the same HSF. Both of the new samples were tested… with virtually identical results as the first one. With sample #2, at full fan speed, cooling improved by maybe 1°C, but at lower fan speeds, it was worse by 1-2C. It’s safe to say there was no appreciable difference in performance. Sample #3 was worse, up to 5°C worse at full 12V fan speed. No further testing was done on that sample. Both of the new sample bases were checked for flatness using a metal straight edge ruler. Like the first sample, neither of the new samples had flat bases. The base of sample #2 was not flat, but it was not consistently convex, much like sample #1. With sample #3, the straight edge made contact with only the rim of the base, leaving a tiny but constant gap through the middle. There was no sign of damage in any of the heatpipes in any of the 3 samples. If pressed to find a reason why these products don’t perform as well as they look like they should, I’d examine…. 1. the flatness of the base. I think this is probably the #1 problem. |
FINAL THOUGHTS
The be quiet! Dark Rock 2 has the look of a heavy duty heatsink from Thermalright, Prolimatech, or Noctua, but unfortunately that’s as far as the resemblance goes. Its performance is decidedly poor compared to today’s various high-end 140 mm fan CPU coolers. be quiet!’s ambitions were sunk by mounting system that doesn’t generate enough pressure and a terribly uneven base. The latter may well be a manufacturing defect, but it doesn’t bode well for retail samples if they can’t get a review unit right.
Even if performance wasn’t an issue, there are other flaws we can’t ignore. Despite the manufacturer’s name, the stock SilentWings fan suffers from an undesirable low-pitched hum throughout its range. The fan clips are designed to accommodate the stock fan’s oddly placed mounting holes, so you can’t swap in a standard 120/140 mm model without modification. Furthermore, for such a thick cooler, we were surprised to find a second fan is not included, or at least the option for one. We’re also not fond of the installation scheme which requires flipping the motherboard upside-down.
Most of be quiet!’s sales occur in Europe; in the UK, the Dark Rock 2 sells for approximately £50 inc. VAT which is quite steep given its capabilities. We can’t recommend it as there are numerous competing coolers on the market that offer far greater value with fewer issues than the Dark Rock 2. It does have one advantage as many of its competitors haven’t yet been updated to support LGA2011. However, if you have the financial latitude to purchase a Sandy Bridge Extreme platform, you’d likely have no trouble shelling out a little extra for a truly excellent heatsink like the Thermalright Archon SB-E.
Our thanks to be quiet! for the Dark Rock 2 CPU cooler sample.
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ADDENDUM #2: The real Final Word
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SPCR Articles of Related Interest:
SpeedFan: A Guide to Universal Motherboard Fan Control
Reeven Kelveros & Arcziel CPU Coolers
Thermalright Archon SB-E 15cm Fan CPU Cooler
Scythe Big Shuriken 2 & Reeven Vanxie CPU Coolers
Fans from Noctua & Corsair at Computex 2012
SPCR’s Updated 2012 Small CPU Heatsink Test Platform
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Discuss
this article in the SPCR forums.
ADDENDUM — 1 Aug 2012: The Real Final Word by Mike Chin
The comments in the forum discussion of this review provoked further communication between bequiet! reps and myself. The last email query was whether our voltage control of the bequiet! PWM fans might have affected the results. I pointed again to our carefully controlled and identical setups for testing and comparison, using either RPM or SPL as reference points. The comparison table in the review makes it very clear. I also reiterated my position that the non-flat, somewhat concave profile of the base was, in my opinion, the #1 weakness, which might be exacerbated by less than ideal pressure between the base and the CPU.
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I decided to test my hypothesis one last time. This time, rather than use the stock bequiet! mounting hardware, I borrowed the rigid, heavy-duty, machined brackets and bolts from a Prolimatech Megahalems cooler. This is probably the best mounting hardware I’ve come across during my >15 years of playing around with CPU heatsinks. Most of the Thermairight and Noctua CPU cooler mounting hardware is just about as good, but what’s particularly useful about the Megahalems hardware is that it is easy to use with many other tower heatsinks.
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The end result was virtually identical to previous results, with an improvement of perhaps 1°C over the best result we recorded for the three samples in previous tests. Time to examine the TIM imprint.
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There’s no question why all the added pressure of the Megahalems mounting did not make any improvement in cooling performance; the center of the base was still not tightly pressed against the CPU because the base of the cooler is concave. Only the edges made tight contact, but that’s not where the heat of the CPU is concentrated, it is in the center. This is the primary reason that the three Dark Pro 2 samples all have such mediocre cooling performance.
One last point: An electronic, infrared, non-contact thermometer was used to check the temperature of various points on the heatsink during the above thermal test. With room ambient at 24°C, and the CPU core reporting 70°C, none of the fins read any higher than ~30°C, and the hottest portion of the heatpipes right at the base of the heatsink read just 37°C, My conclusion: Much of the heat from the CPU was simply not getting into the heatsink.
A photo of a TIM imprint on the base/CPU of a high performance cooler would really put the matter to rest, so here it is.
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The heatsink was turned 90 degrees for the above photo, and the TIM was smuged a bit during uninstallation, but you can clearly see the matching imprints of the TIM on the base and on the CPU. Both have a central area where there is very little TIM; it’s been pushed from the center due to very tight contact. Only around the periphery are there any striations of the TIM. Incidentally, this is a new photo taken just for this addendum, and the heatsink is the original Megahalems sample we tested a couple years ago. Its performance here was 12°C better than the bequiet! Dark Pro 2, with the latter’s stock fan at full speed.
Case closed.
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