be quiet! Dark Rock TF Review

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The firm known as be quiet! is on a roll. We have seen their Silent Base 800 case. We have seen their Pure Rock 4-heatpipe heatsink. So far we have seen high quality stuff. Can they keep it up? Today we are looking at a unique heatsink, one that has a pair of tandem fin stacks. But the fin stacks are set horizontally while the fan or fans blow downward, washing the motherboard and RAM with air. Wonder if it works? Let’s see!

00The parent company for be quiet! is Listan, a German company. Listan has additional brands which may be familiar to you: Revoltec and Xilence. Listan says, “be quiet! is a premium brand manufacturer of power supplies, cases and cooling solutions for your desktop PC.” The brand says this about themselves:

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.

Undoubted fans have a large impact of the noise levels of be quiet! products. Due we are using our specially developed SilentWings fans in nearly all of our range. They are equipped with various noise reducing features. Thanks to these we ensure a really silent operation – our products reach the best balance between cooling performance and a virtually inaudible operation.

Introduction to the Dark Rock TF

Be quiet! Says this about their heatsink:

be quiet! extends its Dark Rock family with a powerful new model in top-flow-format: the Dark Rock TF combines a sophisticated cooler design with the proven SilentWings® technology to successfully cool demanding systems with compact form factors.

The new Dark Rock TF consists of two nickel-plated heat sinks that are interconnected by six performant heat pipes in 6mm format. With this design, the top-flow cooler can carry two SilentWings® fans with a diameter of 135mm and manages a TDP of up to 220 watts at a maximum of 26.7dB(A). The proven fans are decoupled from the heat sinks by rubberised inserts, which suppresses vibrations. For an absolute smooth fan operation, be quiet! uses a long-lasting fluid-dynamic bearing and a silent 6-pole motor.

Due to its dual heat sink design, the Dark Rock TF can be configured so that it even fits into compact systems: the height of the be quiet! cooler can be reduced from 22mm to 108.8mm by removing the upper fan. Fully stocked, the dimensions of the cooler are 162.6 x 140 x 130.8mm (L x W x H). This way, the Dark Rock TF is suitable for various configurations and can cool sophisticated, compact systems just as smoothly as overclocked PCs.

As the Dark Rock TF is part of the high-end cooler line-up of be quiet!, much emphasis is placed on build quality and appearance. The new be quiet! top-flow model is black nickel plated and has been equipped with a high-quality top cover made of brushed aluminum. In addition, the ends of the heat pipes are capped to give the cooler an attractive look. As a result, the Dark Rock TF isn’t just a high performance cooler, but it also has a visual elegance that makes it a match for every system.

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Technical data for complete cooler unit »

Type of cooler

Dark Rock TF

Model number

BK020

EAN code

4260052184233

Dimensions, incl. fan (L x W x H in mm)

162.6 x 140 x 130.8

Weight, incl. fan (g)

810

Heat sink material / finish

Aluminum / Dark
nickel-plated

Socket compatibility

Intel®: 775 / 115X /
1366 / LGA2011(-3) Square ILM
AMD
:
AM2(+) / AM3(+) / FM1 / FM2(+)

Maximum power capacity (W TDP)

220

Number of heat pipes / diameter (mm)

6 / 6

Noise level (dB(A)) @ 50 / 75 / 100% rpm

11.9 / 19.3 / 26.7

Technical data for SilentWings® PWM fans »

Fan dimensions (mm)

135 x 135 x 22

Fan motor
technology

6-pole

Bearing type

Fluid-dynamic

Fan speed (rpm) @
100% PWM

1,400

Noise level (dB(A))
@ 1,400rpm

20.8

Airflow (m³/h) ;
(cfm)

113.8 ; 67.8

Air pressure (mm /
H2O)

1.85

Input current (A)

0.20

Connector

4-pin PWM

Lifespan (h)

300,000

Accessories

Mounting set for Intel® and AMD, Y-cable, Manual (EN, DE, FR, PL, ES, RU)

The fan model is the BQ SIW3-1325-MF-PWM, which would tend to imply that we could call these the “Silent Wings 3” fans.

Unboxing the Dark Rock TF

The Dark Rock TF comes in an ink-impregnated black box that highlights a picture of the heatsink. On the back we have diagrams that explain the heatsink and the fan’s motor.

Box Front

Box Front

Box Back

Box Back

Open the lid and you see that the cardboard is folded into cuffs that hold one of the 135 mm fans in place, so it can’t move or get damaged. The cuffs unfolded and the boxed fan pulled away, you can see where soft springy foam protects the heatsink and the box of small parts. If you’re going to use foam, use this.

Open the Lid and Find a Fan

Open the Lid and Find a Fan

Cushiony Foam

Cushiony Foam

Ah. A side view of the Dark Rock TF at its best. Six heatpipes go to the upper fin stack, four to the lower. We can clearly see the rubber fan cushion on top and bottom of the top fin stack. Unlike some blow-down heatsinks, this uses a full-sized fan top and bottom.

Dark Rock TF

Dark Rock TF

If you tilt the Dark Rock TF you can see how it was put together. Yup, the rubber fan cushions are prominent.

A closeup of the heatpipes show that they are encased in aluminum. No heat escaping except through those fins. Are they clamped or soldered under there? If clamped, how good is that clamping?

Through the Top Fin Stack`

Through the Top Fin Stack

No Heatpipes Showing

No Heatpipes Showing

The first picture shows the backplate and a PWM Y-cable for those with motherboards that only have a single fan header for the CPU. The second picture shows more small parts: two arms of the mount, spacer clip, nuts, tiny mounting arm screws, AMD mounts, through bolts, combination nut-bolts, screws for mounting the heatsink on an LGA-2011, a wrench and a tube of TIM.

Backplate and PWM Y-Cable

Backplate and PWM Y-Cable

Other Small Parts

Other Small Parts

The fan. This fan has its flange mounted amidships. Unlike fan with edge-mounted flanges, this single flange fan can be mounted in both directions. But because this is a “special” fan and the clips are designed for it, you cannot use this heatsink with other fans.

When you compare this exhaust side picture to the initial intake side picture, you will see that both sides have air grooves.

Silent Wing 3, Intake

Silent Wing 3, Intake

Silent Wing 3, Exhaust

Silent Wing 3, Exhaust

Here is a picture of the top heatsink, complete with fan cushions.

The next picture shows what the top of the heatsinks looks like with a fan on it. We have a problem. Only one wire goes into the screw hole. If a wire U went in, it would hold the fan better. These single-wire grips do not hold the fan. It’s too easy for the clip to come off while you are trying to mount the fan on the fin stack.

Top Fin Stack

Top Fin Stack

Fan on Top Fin Stack

Fan on Top Fin Stack

Here is a side view with the fans clipped on the top fin stack. Can you spot another problem here? That’s right – no handle on the clips.

The next picture show how you mount the fan: you must use both thumbs to press on the green arrows. What’s that you say? You want to reposition the fan? That is a difficult job. Try placing the blade of a flat screwdriver at the places marked by the red arrows. You will probably work the fans free.

Fans and Fan Clips

Fans and Fan Clips

Fan Clip Pressure Points

Fan Clip Pressure Points

Perched on a fan box, you can see the plastic surface protector for the contact surface of your heatsink. When it is peeled off, the contact surface is smooth, but not a mirror. See how dark it is? A nice touch.

Contact Surface Protection Film

Contact Surface Protection Film

Dark Contact Surface

Dark Contact Surface

These two pictures capture the slight convexity of the Dark Rock TF. It is mostly flat when the razor blade is aligned with the heatpipes, but curved ever so slightly cross-ways to the heatpipes. Later testing was “spin test positive:” when you put the heatsink on a CPU unprotected and not encumbered with TIM, it will spin freely. This is probably our most sensitive test for convexity.

Blade Aligned with Heatpipes

Blade Aligned with Heatpipes

Blade Across the Heatpipes

Blade Across the Heatpipes

Now be quiet! expects you to screw the two arms onto the heatsink with those tiny little screws. Now where have I seen that design before? Of course! This mount was the subject of a photo essay I did – in 2011(!). Actually, I took the pictures in December of 2010. That’s nearly five years ago. Take some time and look at the pictures in that photo-essay. This is not just a similar mount. It is the same mount. In the end, I decided that it would be better to mount the motherboard to the heatsink, rather than mount the heatsink on the motherboard.

The second photo shows the backplate mounted on the heatsink without a motherboard in the way. You can see where those plastic clip-spacers go.

Mount Splayed Out

Mount Splayed Out

Backplate on top of Mount

Backplate on top of Mount

Here are the clip-spacers as they will appear on a motherboard. The second picture shows a practice motherboard mounted on a heatsink.

Where You Put the Spacers

Where You Put the Spacers

Motherboard on top of Heatsink

Motherboard on top of Heatsink

This picture shows you how much RAM clearance you get with this heatsink – a lot. It looks nice, too.

Just one problem. I really did not want to take my motherboard out of its testing rig. Too much trouble. So I held the heatsink up to the CPU, found the screws, and started the upper two screws. I then let gravity do its work to hold the heatsink in place while I screwed in the mount to its place on the CPU. I can’t really show you photos of this, so you get a story instead.

RAM Clearance

RAM Clearance

Testing Setup

CPU

Intel i7 4790K @ 4.5 GHz

Vcore

For 4.5 GHz, Set to 1.23 Volts, read at up to 1.248 Volts

Vrin

At 4.5 GHz, set to 1.8 Volts, read at down to 1.704 Volts

GPU

Intel HD Graphics 4600, integrated into the i7 4790k

Motherboard

Gigabyte Z97X Gaming-7

RAM

Crucial Ballistix Sport Ultra Low Profile; 2 x 4 GB – 8 GB total

SSD

Samsung 840 EVO 500 GB + 1 TB

PSU

Seasonic SS-460FL 460W Fanless

Heat Stress Software

Linpack with AVX2 – LinX 0.6.5 user interface

Operating System

Windows 10, 64-bit

Core Temp Log

Real Temp

Ambient Temp Log

Digital TEMPer USB Thermometer, with logging software

Package Watt Log

Intel Power Gadget 3.0

Sound Pressure Meter

Tenma 72-942

Fan Airflow Meter

Extech AN100 Anemometer

The Dark Rock came from be quiet! The other comparators were provided by their respective OEM’s, except for a Prolimatech Megahalems, which was purchased retail at the end of 2009, with a Prolimatech Genesis and a Noctua NH-D14 SE2011 that were both purchased retail at the end of 2013. Each heatsink or AIO was mounted on the night before testing. This gave the TIM most of a day to do any migrating it was going to do.

Linpack runs in surges. When the temperature is graphed, you see ragged plateaus. In looking for cooling solutions, you want to know how well a heatsink cools those plateaus. So at 4.5 GHz the temps under 70 °C (the valleys) were ignored in analyzing core temps. At 4.4 GHz the temps under 60 °C were ignored.

Each test run was 30 minutes in duration. The last 20 minutes of each run was measured, and the core temperature logs were analyzed in Open Office spreadsheets. An Intel chip reports its temps in one degree increments, so for best accuracy these reports should be averaged in aggregate. Here the core temps were measured once a second, resulting in 1200-line spreadsheets.

The digital thermometer measuring air temp reported its measurements in increments of 0.1 °C. The ambient temperature was measured every five seconds, resulting in 240-line spreadsheets. The mean ambient temp was subtracted from the mean core temps, resulting in a net temp for each run. Finally, the three net temps were averaged.

The Sound Pressure level was measured 1 meter from the heatsink, with the motherboard set vertically, the way it would be in your case. The ambient noise for this testing was 31 dBA. So the net SPL is the sound pressure level measured at 1 meter, less 31 dBA.

Three combinations of fans were tested on the Dark Rock TF. The push fan only setup and the two-fan combination were 13.8 cm tall, starting at the motherboard. It included the top fan and rubber cushions that the fans rested on. The pull fan setup was 11.5 cm, starting at the motherboard, not including the rubber fan cushions.

Two Fans

Two Fans

Underfan Only -- 11.5 cm Tall

Underfan Only — 11.5 cm Tall

Results of Testing

This blow-down heatsink with its nearly flat bottom managed to stay in the major league. The interesting contrast here is between the top-down fan position and the middle fan position. The middle fan position produced better cooling and quieter operation. And I mean quiet. The SPL meter read stuff I couldn’t hear. Be quiet has managed to make a fan that made hardly any noise. Even when it was on top, a single fan could barely be heard. Two fans you could hear; but the combination was still quiet.

DarkRockTF

Availability

At the time of publication, this heatsink is available from Newegg for $80 with free shipping.

Conclusions

The fact that the Dark Rock TF heatsink did not excel in these results is hardly surprising. This is the major league of coolers. This heatsink was competing with tandem fin stack heatsinks and an AIO cooler. A down-blowing heatsink is doing well if it merely makes it into this league. And, incontrovertibly the Dark Rock TF made it into the major league.

A low-profile heatsink like this is somewhat of a unique product. You use it when you have a skinny case. Put another way, you want a blow-down when your case is low-down.

The Dark Rock TF is a beautiful heatsink. From the dark bottom of the contact surface to blackened top of the fin stack, be quiet! has spared no effort to make this a beautiful cooler, colored consistently with a dark theme. They have spared no detail in workmanship, from the fan cushions to folding in a second fin stack. What a marvelous idea that was. And the fans are a study in quietness.

But this heatsink has two glaring problems. The first problem is the fan clips. They are difficult to manage. They require both hands to put them in place, and it is still not easy. And removing the fan clips is worse.

A worse problem is the mount. It is the same mount you find in a heatsink that is no longer in production. It is a primitive device from five years ago. If you are going to mount this heatsink, take the motherboard out of your case; only then put the motherboard on the mount. By the way: that mount you saw in the photo-essay? It has not moved in five years. Too much trouble to remount the beast. That should tell you something about the mount.

It is ridiculous to find this mount on an otherwise lovely heatsink. It is as if the be quiet! engineers designed the heatsink without thinking about how it would mount onto the motherboard. The Dark Rock TF does not merit such a pathetic mount. Don’t forget the fan clips. They are just plain bad.

There is no excuse for be quiet! When we look at the Pure Rock, their entry-level heatsink we see fine fan clips and a really good mounting system. Especially at the higher price point, you expect better. For $5 more than the Dark Rock, for example, you can get the Noctua NH-C14S, which has the same height, and further has their world-class mounting system.

This otherwise splendid heatsink does not deserve these clips or that mount. Until be quiet! improves those to, say, the level of a Pure Rock, you would do well to think twice before getting this heatsink. When they do make those improvements, then the Dark Rock TF will definitely be one quiet heatsink well worth having.

end

Dark Rock TF Pros

  • Very, very quiet.
  • Uses two fin stacks, so
  • Using the fan underneath produces better cooling than having the fan on top.
  • The fans sound softer than their SPL measurements
  • Care has been taken to make the heatsink beautiful
  • Very little convexity in the contact surface, making this heatsink relatively safe to use
  • The manual is online

Dark Rock TF Cons

  • The mount is old, primitive and was bad five years ago. There is no excuse for it now.
  • The fan clips are a pain to use

Click the stamp for an explanation of what this means.

Ed Hume (ehume)

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