be quiet! Shadow Rock Slim 2 CPU Air Cooler Review

Manufacturer: be quiet! be quiet! Shadow Rock Slim 2 CPU Air Cooler Review

Upon reflection, it seems that I have historically begun articles with comments about the names of the various products I’ve reviewed for PC Perspective.  I do not believe that I’ll break that trend today as be quiet! seems to be applying the current enclosure naming trend to its CPU coolers.

Actually, it may be a little worse than the enclosure market as it was extremely difficult to remember as I was entering data which be quiet! cooler was which.  Between the Dark Rock Pro, the Shadow Rock 3, the Pure Rock Slim 2, and now the Shadow Rock Slim 2, my spreadsheet became dizzying.

With that out of the way, I’ll actually cease to complain about the name and talk about what really matters: the product itself. The Shadow Rock Slim 2 is a 161mm tall cooler that utilizes four 6mm, direct contact heatpipes. The Slim 2 and its predecessor, the Slim, have a very similar appearance, but the updated model actually sells for $5 US less ($45.90 MSRP), which also places it at $5 US less than its chunkier sibling, the Shadow Rock 3.

Shadow Rock Slim 2 Noise Chart
Product Specifications


  • Model: Shadow Rock Slim 2
  • Overall dimensions without mounting material (L x W x H):  74 x 137 x 161 mm
  • Total weight: 0.69 kg
  • TDP: 160W
  • Socket compatibility:
    • AMD AM4 / AM3(+)
    • Intel 1200 / 2066 / 1150 / 1151 / 1155 / 2011(-3) Square ILM
  • Fan: 1x silence-optimized be quiet! fan
  • Overall noise level @ 50/75/100% RPM: 11.5 / 18.7 / 23.7 dB(A)


  • Dimensions (L x W x H): 52 x 130 x 161 mm
  • Number of fins: 53
  • Fin material: Aluminum
  • Base material: Copper
  • CPU contact surface: Heat pipe direct touch
  • Heatpipe number / Diameter (mm): 4 / 6
  • Color: Silver
  • Surface treatment: Brushed


  • Fan dimensions: 135 x 135 x 22 mm
  • Speed @ 100% PWM /12V: 1400 RPM
  • Bearing technology: Rifle
  • Motor technology: 4-pole fan motor
  • Rated Voltage: 12V
  • Input current: 0.11A
  • Input power: 1.32W
  • Connector: 4-pin PWM
  • Cable length: 220 mm
  • Lifespan (h / 25°C): 80,000
$45.90 USD
Manufacturer Description
“be quiet! Shadow Rock Slim 2 is the space saving CPU cooler for gaming, multimedia and graphics-intensive compact PCs. With high performance, the famously silent be quiet! operation and an unmatched price-performance ratio, Shadow Rock Slim 2 is a best choice in this category.”

The Shadow Rock Slim 2

Shadow Rock Slim 2 Noise Chart

When I initially examined the cooler, it visually reminded me of the old Thermalright Ultra Extreme (TRUE) cooler that ruled the air cooling roost about a decade ago – basic, but superbly designed. Like all the be quiet! coolers I’ve used and tested over the last few years, the Shadow Rock Slim 2 gives every visual and tactile impression of being a high quality piece of equipment.

Shadow Rock Slim 2 Noise Chart

While the contact plate on the Shadow Rock Slim 2 was not as well machined as on the last be quiet! cooler I tested, it was still very flat and smooth for a direct contact type surface. The included 135mm fan continues the trend, and is a step above the cheap, sleeve bearing fans you would find on almost any similarly priced cooler. There is more to the fan, but I’ll come back to it later.

Shadow Rock Slim 2 Noise Chart

From the information I have been able to find, the biggest difference between the Shadow Rock Slim 2 and its predecessor, is the use of be quiet’s updated mounting system. In a previous review, I mentioned that although I really like most of the be quiet! products I have used, I dislike their mounting systems. While their new mounting method is better than their old, and very secure, it is still miles away from the likes of Noctua and Scythe when it comes to ease of installation. Luckily, with the Shadow Rock Slim 2, the biggest problems with their mounting procedure aren’t encountered because the cooler is so…well…Slim.

Without the fan mounted, it is quite easy to access the two screws on the crossbar to tighten the cooler to the mounting brackets. It would still be better if the two crossbar screws were captive, but it is not as large a problem on this unit as on others I’ve tested.

Performance Testing

For testing, I ran the OCCT small data set, extreme stress test for 20 minutes on an open test bed.

Test System Specs:

  • AMD Ryzen 7 3800X Processor
  • ASRock X570M Pro4 Motherboard
  • 16 GB (2×8) G Skill Trident Z 3333 (@ DDR4-3600) Memory
  • Zotac GTX 1650
  • Sabrent Rocket 4 500 GB NVMe SSD
  • IC Diamond Graphite Thermal Pad (used on all coolers for consistency in testing)
  • All tests conducted at a controlled ambient temperature of 24.5 C

To begin the performance portion of the review, there is one major thing that needs to be addressed, and it relates to the fan (I did say I’d come back to that). I’m uncertain that I can truly convey in text how big a point this is, so I’ll yell:


Shadow Rock Slim 2 Noise Chart

At the fan’s maximum speed of 1400 rpm, it is barely audible over ambient noise, and that is on an open test bed. Inside an enclosure that uses its own fans, this cooler would be effectively silent. At any speed from around 1100 rpm down, I essentially had to place my ear next to cooler to hear it. Even when it is audible at max speed, the tone of the fan is actually pleasant. be quiet! did an amazing job on the design of this fan.

Of course, it will not matter how quiet it is if it is unable to perform its primary function of dissipating the heat generated by a CPU. Well, it does a perfectly adequate job there as well.

Shadow Rock Slim 2 Thermal Chart

Of course with the limited fin mass of the slim design, and only 4 heatpipes, the Shadow Rock Slim 2 isn’t going to win any overclocking competitions, but it handled a Ryzen 7 3800X very well, performing almost equally to its larger brother, the Shadow Rock 3, while taking the latter’s quiet crown.


be quiet! continues to surprise me with their most recent releases. The tiny Pure Rock Slim 2 that I reviewed a few months ago shattered what I thought such a small cooler could achieve at such a low price. Now, the Shadow Rock Slim 2 has almost matched the larger, and more expensive, Shadow Rock 3 in performance, and does that while being practically silent.

Shadow Rock Slim 2 Thermal Chart

The Shadow Rock Slim 2 is an excellent purchase and it brings be quiet! yet another PC Perspective Gold award.

pcper gold award

Review Disclosures

This is what we consider the responsible disclosure of our review policies and procedures.

How Product Was Obtained

The product is on loan from be quiet! for the purpose of this review.

What Happens To Product After Review

The product remains the property of be quiet! but is on extended loan for future testing and product comparisons.

Company Involvement

be quiet! had no control over the content of the review and was not consulted prior to publication.

PC Perspective Compensation

Neither PC Perspective nor any of its staff were paid or compensated in any way by be quiet! for this review.

Advertising Disclosure

be quiet! has purchased advertising at PC Perspective during the past twelve months.

Affiliate Links

This article contains affiliate links to online retailers. PC Perspective may receive compensation for purchases through those links.

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