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be quiet! Shadow Rock Slim CPU Cooler

A slim tower cooler built in the same vein as the Noctua NH-U14S, the bequiet! Shadow Rock Slim is lighter, more affordable, and surprisingly proficient.

March 10, 2014 by Lawrence Lee

Product
be quiet! Shadow Rock Slim
CPU Cooler
Manufacturer
be quiet!
Street Price
£35 (~US$45)

The Shadow Rock Slim is, as the name indicates, a slim CPU cooler, but as it
uses a traditional tower design and a large fan, it’s in no way petite. It’s
essentially be quiet!‘s take on the Noctua
NH-U14S
, a sleek tower designed not to interfere with memory slots and
board components close to the CPU socket, without compromising performance.
It doesn’t utilize a 140 mm fan, however — the stock fan falls 3 mm short
of that diameter. Surprisingly, the size isn’t even the most interesting thing
about it; its oddly placed mounting holes and heavily ridged blades stand out
even more.


The Shadow Rock Slim.

The heatsink itself uses fewer materials, forgoing the heavy top-to-bottom
nickel-plating adopted by Noctua and other high-end heatsink manufacturers.
The resulting product is lighter and more affordable but that doesn’t necessarily
mean it’s an inferior cooler. The Thermalright
HR-02 Macho
and Scythe Mugen
4
proved that a more traditional unplated composition can be just as
effective. be quiet! claims the Shadow Rock Slim can adequately cool
a CPU with a TDP of 160W which isn’t too far-fetched assuming there are no base
or mounting problems.


The box.


Contents.

Inside the box is the heatsink and fan, a brief assembly guide, a tube of thermal
compound, a backplate and necessary mounting hardware, and a second set of fan
clips. Interestingly, the two sets of fan clips are not identical — the
pair pre-installed are of course, designed to be used with the unusual placement
of the stock fan’s mounting holes. The additional set of clips are actually
bigger, made to accommodate a standard 120 x 25 mm fan. This presents a dilemma
for users who wish to run a dual fan configuration.

Our last experience with a be quiet! heatsink, the Dark
Rock 2
, was plagued with problems. We went through several samples that
gave us poor results each and every time. After extensive testing we eventually
concluded an inconsistent, non-flat base was the issue. Undeterred, the manufacturer
has sent us another cooler to review, a newer, smaller model, the Shadow Rock
Slim. We can only hope it doesn’t suffer from the same issue.

be quiet! Shadow Rock Slim: General Specifications
(from the product
web page
)
Overall dimensions without mounting material (L x W x H), (mm) 74 x 137 x 161
Total weight (kg) 0.73
TDP (W) 160
Socket compatibility Intel: LGA 775 / 1150 / 1155 / 1156 / 1366 / 2011
AMD: 754 / 939 / 940 / AM2(+) / AM3 (+) / FM1 / FM2 (+)
Warranty (Years) 3
Heatsink Specifications
Dimensions (L x W x D), (mm) 52 x 130 x 161
Number of fins 52
Fin material Aluminum
Base material Copper
CPU contact surface CNC machined
Heatpipe number, Diameter (mm) 4, 6
Fan Specifications
Dimensions (mm) 135 x 135 x 22
Speed @ 100% PWM (rpm) 1400
Air flow @ 12V (cfm, m3/h) 67.8, 113.8
Air pressure @ 12V (mm H2O) 2.1/1,23
Overall noise level (dB(A)) @ 50/75/100% (rpm) 11.5 / 18.7 / 23.7
Bearing type Rifle
Rated voltage (V) 12
Input current (A) 0.11
Input power (W) 1.32
Connector 4-pin PWM
Cable length (mm) 220
Lifespan (h / 25°C) 80.000

PHYSICAL DETAILS

The Shadow Rock Slim is composed of a nickel-plated copper base
soldered to four 6 mm thick copper heatpipes and 52 friction-fit aluminum fins.
By our measurements, the heatsink’s dimensions are 13.0 x 5.2 x 16.0 cm (L x
W x H) and its weight is 580 grams (720 grams including the stock fan).


The heatpipes are arranged in four rows and the fins’ contours are somewhat wavy rather than straight. The fins are 0.42 mm thick and spaced 1.73 mm apart, on average.


The heatsink body is 52 mm thick, equaling the Noctua NH-U14S, currently SPCR’s best performing slim tower CPU cooler.


A thick brush aluminum plate at the top keeps the heatpipes in place and adds a decorative touch.


The center of the fin-stack is depressed in the shape of the Batman logo.


The plate above the heatpipes is ridged to dissipate a bit of extra heat. This tertiary heatsink feature is commonly found on Scythe products.


The base is nickel-plated and the surface is very flat. A lot of machining has been done to sand it down to a mirror finish but there are still some fine lines visible. The somewhat convex shape of the Dark Rock 2 base is nowhere to be found.


The fan is of a nonstandard size (137 x 137 x 22 mm) and the mounting holes are located on an octagonal frame extending from the center of an inner circular frame.

INSTALLATION

The most critical aspect of installation is that the heatsink
be securely mounted. A firm mounting results in good contact between the cooler’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.


The mounting system is rather convoluted, with three metal pieces screwed to one another for each mounting hole. Worst yet, a wrench is needed to tighten the assembly topside.


The nuts are used to finish the install, mating the mounting clips to the rest of the system but with three interlocking pieces it’s difficult to tighten properly. We ended up using pliers to keep the nut from moving and tightening the opposite side with a screwdriver. The Dark Rock 2, used screws that went through the backplate and linked up directly with the mounting clips.


Positioning of the mounting clips underneath rather than on top of the mounting plate usually results in poor performance. Here you can see the mounting clip slightly pulling away from the base. This extra pressure would be better served pulling the heatsink down to make better contact with the CPU.


Fully assembled on our LGA1366 testing platform.


The heatsink’s slim profile kept the fan well away from the memory slots on our test motherboard.


The thermal compound imprint left on the CPU shows very good contact at
the center, where it’s most needed. The residual TIM is thicker at the
sides indicates poorer contact. Note, this is a picture taken on our LGA1155
platform, though it was tested on the LGA1366 platform where it left a
similar imprint (long story).

TESTING

Before thermal testing, we took some basic physical measurements.

Approximate Physical Measurements
Weight
580 g (+140 g with stock fan)
Height 160 mm
Fin count 52
Fin thickness
0.42 mm
Fin spacing
1.73 mm
Vertical Clearance*
48 mm
* measured from motherboard PCB to bottom
fin of heatsink

 

Large Heatsink Comparison:
Average Fin Thickness & Spacing
Heatsink
Fin Thickness
Fin Spacing
SilverStone Heligon HE02
0.52 mm
3.30 mm
Thermalright HR-01 Plus
0.45 mm
3.15 mm
Thermalright HR-02 Macho
0.34 mm
3.12 mm
Thermalright HR-22
0.53 mm
2.74 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
GELID Tranquillo Rev.2
0.40 mm
2.30 mm
Phanteks PH-TC12DX
0.39 mm
2.30 mm
GELID GX-7 Rev.2
0.31 mm
2.25 mm
Phanteks PH-TC14PE
0.40 mm
2.21 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 Ashura
0.43 mm
1.97 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
SilverStone Tundra TD03 (radiator)
0.43 mm
1.86 mm
Swiftech Polaris 120
0.43 mm
1.85 mm
SilverStone Argon AR01
0.30 mm
1.85 mm
Thermalright Venomous X
0.53 mm
1.84 mm
Scythe Mugen 4
0.30 mm
1.82 mm
Noctua NH-C14
0.38 mm
1.79 mm
Enermax ETS-T40
0.40 mm
1.79 mm
Scythe Yasya
0.32 mm
1.78 mm
be quiet! Shadow Rock Slim
0.42 mm
1.73 mm
SilverStone Argon AR03
0.42 mm
1.72 mm
Noctua NH-U14S
0.42 mm
1.72 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 like this one is done on our
LGA1366 heatsink testing platform
, while smaller coolers are tested
on 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)

Key Components in LGA1155 Heatsink Test Platform:

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
Speed
SPL@1m
12V
1250 RPM
28~29 dBA
9V
990 RPM
21 dBA
8V
880 RPM
18 dBA
7V
770 RPM
15~16 dBA
6V
660 RPM
13 dBA

 

Reference Nexus 120 mm fan
Anechoic chamber measurements
Voltage
Speed
SPL@1m
12V
1080 RPM
16 dBA
9V
880 RPM
13 dBA
7V
720 RPM
12 dBA

 

Reference Nexus 92 mm fan
Anechoic chamber measurements
Voltage
Speed
SPL@1m
12V
1470 RPM
17 dBA
9V
1280 RPM
14 dBA
7V
1010 RPM
12 dBA

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 CPU heavily, generating more heat than most real applications.
    All instances are used to ensure full stress.
  • 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 is off to ensure that system noise
do not skew the measurements.

Load testing was accomplished using Prime95 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

Specifications: be quiet! Shadow Rock Slim Stock Fan
Manufacturer be quiet! Power Rating 4.8 W
Model Number BQ SIW3-13525-MR-PWM Airflow Rating 67.8 CFM
Bearing Type Rifle Speed Rating 1400 RPM
Frame Size 137 x 137 x 22 mm (120 mm holes) Noise Rating 23.7 dBA
Hub Size 46 mm Header Type 4-pin PWM
Blade Diameter 129 mm Starting Voltage 4.0 ~ 4.5 V
Cable Length 20 cm Weight 140 g
Corner Type Open Retail Availability No

Additional notes:

The Shadow Rock Slim stock fan is characterized by a large hub, blades ridged on both sides, and a wide angle between the slightly curved struts and the blades’ trailing edges. On the exhaust side, the round frame has a soft/rubberized surface that presumably gives it some anti-vibration properties. The mounting holes are located on a second frame protruding outward at the center in an octagonal fashion.

Stock Fan Measurements
Voltage
Speed
SPL@1m
12V
1380 RPM
26 dBA
9V
1070 RPM
19 dBA
8V
960 RPM
16 dBA
7V
850 RPM
13~14 dBA
6V
730 RPM
12~13 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

As the stock fan has PWM capability, a low starting voltage, and a top speed
of just 1400 RPM, the fan speed range available is quite good. At top speed
we recorded a noise level of 26 dBA@1m which is low compared to most stock CPU
fans. Dialing the speed back to 9V/1070 RPM was enough to make it quiet by our
standards and it became almost inaudible at 6V/730 RPM. It can get even quieter
as the starting voltage is well under 5V and we coaxed it down to a low of 380
RPM on PWM control.

The fan had interesting acoustics, producing mostly turbulent noise (the sound
of rushing air) at top speed. At 9V, much of the turbulence dissipated, leaving
behind a mildly annoying low frequency drone. At 8V, the droning suddenly vanished,
as evinced by the disappearance of a ~320 Hz tonal spike in our acoustic analysis
above. The resulting noise was much smoother, with a mostly broadband profile,
and its prevalence continued at both 7V and 6V. Under 8V (about 1000 RPM), its
acoustics were top-notch.

TEST RESULTS

Test Results: be quiet! Shadow Rock Slim
Fan Voltage
Stock Fan
Reference Fan
SPL@1m
Thermal Rise
SPL@1m
12V
26 dBA
37°C
38°C
29 dBA
9V
19 dBA
40°C
39°C
22 dBA
8V
16 dBA
41°C
41°C
19 dBA
7V
13~14 dBA
42°C
42°C
15 dBA
6V
12~13 dBA
44°C
44°C
13 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

The Shadow Rock Slim was an excellent cooler, generating a thermal rise above ambient of 44°C at 6V and 37°C at 12V. The stock fan performed almost identically to the Noctua NF-P14, producing the same results at 6V, 7V, and 8V, while only 1°C separated the two fans at 9V and 12V. However, the stock fan was quieter at every level, giving it the overall edge.

HEATSINK COMPARISON TABLES

°C Rise Comparison: CPU Coolers with Single Stock Fan
SPL (dBA@1m)
20
19
18
17
16
15
14
13
12
11
Thermalright Archon SB-E
39
40
43
Thermalright HR-02 Macho
39
40
41
43
Scythe Mugen 4
40
42
45
Noctua NH-U14S
38
40
43
be quiet! Shadow Rock Slim
40
 
41
42
Scythe Yasya
40
43
Cogage TRUE Spirit 1366
41
43
46
Zalman CNPS10X Quiet
40
42
47
Scythe Ashura
42
44
Cooler Master Hyper 212 Plus
41
44
54
Silverstone Argon AR03
43
48
Scythe Ninja 3
44
46
SilverStone Argon AR01
44
50

Compared to other coolers that ship with a single stock fan, the Shadow Rock Slim put up a tough fight, landing in fifth place, one spot behind the Noctua NH-U14S.

°C Rise Comparison:
CPU Coolers with Single 140 mm Reference Fan
Heatsink
Fan voltage / SPL @1m*
9V
(~21 dBA)
7V
(~15 dBA)
6V
(~12 dBA)
Thermalright Archon SB-E
37
40
42
Noctua NH-U14S
38
41
44
be quiet! Shadow Rock Slim
39
42
44
Thermalright HR-22
39
42
44
Prolimatech Armageddon
39
42
45
Scythe Mugen 4
39
42
45
Thermalright HR-02 Macho
39
43
45
NZXT Havik 140
40
43
47
Scythe Ashura
41
44
46
Noctua NH-C14
(top mounted)
40
44
48
Noctua NH-C14
40
44
49
Thermalright Silver Arrow
39
45
49
Phanteks PH-TC14PE
42
45
48
SilverStone Heligon HE02
45
48
50
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.

Paired with our reference 140 mm fan, the Shadow Rock Slim jumped ahead to third place, once again, behind the NH-U14S.

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 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.

FINAL THOUGHTS

The be quiet! Shadow Rock Slim delivers superb performance, in spite
of its slightly smaller size and simpler construction compared to most high-end
coolers. Our sample didn’t suffer from any of the issues that plagued our testing
of the Dark
Rock 2
. Furthermore, the newer fan model is an improvement, producing
more pleasant acoustics below the 1000 RPM level, and the heatsink’s slimmer
body makes memory interference a non-issue.

While an excellent cooler, the Shadow Rock Slim has some irksome design issues.
Compared to the Dark Rock 2, the mounting system has become more complicated,
with two extra pieces that force users to flip the motherboard on its side to
tighten the assembly properly. You have to work a screwdriver on one side and
a wrench/pliers on the other. The mounting clips are also too thin, bending
away from the base when secured. Using thicker clips or moving them above the
base would ensure all the pressure they apply is put to good use. Finally, be
quiet!
‘s use of a nonstandard fan frame might be infuriating to some. A
second set of clips for standard 120 mm fans is included, but only one. If you
want to use dual fans, you have to pair the stock fan with a different model,
undoubtedly resulting in intermodulation effects.

The Shadow Rock Slim is currently selling overseas for approximately £35,
which should work out to about US$45~50 based on relative CPU cooler
price differences between North America and Europe. That would undercut its
closest competition, the Noctua
NH-U14S
, by around US$20~25. It lacks Noctua’s fit and finish
but near-identical cooling proficiency and lower price makes it a far better
value.

Our thanks to be quiet!
for the Shadow Rock Slim CPU cooler sample.


be quiet! Shadow Rock Slim
receives the SPCR Editor’s Choice Award

* * *

SPCR Articles of Related Interest:

Thermalright HR-22 CPU Heatsink
Noctua NH-U14S Slim 140mm Tower Cooler
Scythe Ashura CPU Cooler
SilverStone Tundra TD03 Liquid CPU Cooler
Scythe Mugen 4 CPU Cooler: Scythe Strikes Back
NoFan CR-95C Copper Fanless CPU Cooler

* * *

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this article in the SPCR forums.

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