If you've been looking to buy a low-profile CPU cooler for your compact PC, we've got a hunch you're going to like what we have in store for you in this article. There are plenty of reviews out there testing the full range of coolers on the market, including most of the models we'll be profiling in this article. But oftentimes, what you'll find is a one-off review, which compares a particular cooler to whatever other coolers a particular media outlet has tested, be they similar or completely different. And when it comes to low-profile coolers, it's typically the latter, which means you learn that the $40 low-profile cooler you've been eyeing performs a whole lot worse than a $120 liquid cooler. And therein lies the problem with typical cooler reviews on the Internet; they just aren't all that helpful in actually choosing the right cooler for your particular needs.

And we're on a mission to fix all that! In mid-2015, we published a comprehensive guide to CPU coolers, benchmarking six coolers featuring vastly different designs, from a low-profile 92mm model to a dual 120mm liquid cooler, using Intel's Haswell-based Core i7-4770K as the test platform. That article was intended to give readers a sense of the range of coolers out there, rather than to choose the one best among many divergent designs. We followed up on that article with a 140mm Cooler Shootout to help our readers identify the very best 140mm coolers on the market, and now we're doing the same for low-profile coolers. We believe that our readers are always going to be best served when we compare a number of products in the same price and performance classes, and more importantly, when we provide a deep dive into why some coolers perform better than others in a given test scenario.

Another pet peeve of ours is that many cooler reviewers use the same old PC platform they've been using for years, which allows them to compare coolers they tested 5 years ago to a cooler they're testing today. But today's CPUs aren't comparable to older CPUs. In fact, the Core i5-6600K we're using for this article runs much cooler than previous CPUs, changing the cooling equation substantially. Yes, you can go overboard with ultra-high-end coolers that could easily cool hotter-running CPUs from a few years ago, but why would you? And that's why low-profile coolers deserve a fresh look on a modern platform, because in reality, they're all just about any PC user really needs, even if most builders are drawn in by the allure of big radiators and multiple fans.

Luckily, due to all the groundwork we've laid with our previous CPU Cooler Reviews, a number of leading cooler manufacturers were eager to send in their best low-profile models for a shootout in which only one (or perhaps a few!) would survive. Here are the nine coolers we're testing, along with their retail prices as of our publication date:

The Contenders

  1. Intel Reference Cooler (bundled with the Intel Core i7-4770K Processor)
  2. Noctua NH-L9x65 - $50 (special thanks to Noctua for providing this review sample)
  3. Noctua NH-L12 - $57 (special thanks to Noctua for providing this review sample)
  4. Reeven Brontes - $35 (special thanks to Reeven for providing this review sample)
  5. Reeven Steropes - $46 (special thanks to Reeven for providing this review sample)
  6. SilverStone NT08-115X - $23 (special thanks to SilverStone for providing this review sample)
  7. SilverStone AR06 - $40 (special thanks to SilverStone for providing this review sample)
  8. SilverStone NT06-Pro - $55 (special thanks to SilverStone for providing this review sample)
  9. Thermalright AXP-100 Muscle - $50 (purchased at retail)

Below you'll find the specifications for each of the coolers we tested. Note that weights were taken on our own scale, as manufacturers do not have a standardized method for reporting weights. Some include just the heatsink, others the heatsink and fan, and others still the entire assembly, including brackets. Our weight measurements include the components that contribute to performance: the heatsink and fan.


To build the suspense, we're going to give away just a little bit of our conclusion right up front: three of these coolers will suffer disqualifications for failing to fit properly on our mini-ITX test platform, and two of these coolers will be declared winners. Place your bets, ladies and gentlemen, because things are going to get interesting!

Test Method 

Test System

As we noted above, we're using a current-gen benchmarking system featuring Intel's Skylake platform. Here's the setup we used to rate our contenders:

  1. CPU: Intel Core i5-6600K (overclocked to 4.4GHz)
  2. Motherboard: Asus Z170I Pro Gaming
  3. Memory: Corsair Vengeance LPX 2x8GB DDR4-3000
  4. Solid-State Drive: Samsung 850 Evo 500GB
  5. Video Card: Asus GeForce GTX 1070 8GB Founders Edition
  6. Power Supply: SilverStone PS-ST85F-PT 850W Platinum
  7. Case: Corsair Carbide 500R ATX
  8. Operating System: Windows 10 Home

To add a bit more challenge, we overclocked our 6600K to 4.4GHz. In past reviews, we've provided both stock and overclocked benchmarks, as do many other review sites, but in our opinion, trying to draw out differences between coolers using a stock-clocked Skylake CPU amounts to splitting hairs. There's just not much cooling needed, so any difference might as well be within the margin of error. If you're using a clock-locked processor or you're not interested in overclocking your unlocked processor, you can honestly use any cooler, even Intel's reference cooler included with non-K processors (Intel no longer provides one with K processors). There's simply no way you'll be able to overheat your CPU, and believe it or not, your system will run pretty quietly too, as we'll show you in this review.

Eagle-eyed readers will note that we chose an unusual combination of a mini-ITX motherboard and an ATX case. We used an ITX motherboard to put each cooler's small form factor credentials to the test, while using an ATX case to ease our burden in switching out coolers. As it turns out, the case we initially planned on using, the SilverStone Raven RVZ01-E, doesn't provide access to the rear of the motherboard, meaning the motherboard would have to be removed for each installation - a major pain when installing so many coolers over a short period of time. More importantly, perhaps, is the fact that after having gone through the process of actually installing all the coolers, we found that several would have been impossible to properly install without access to the rear of the motherboard. While we had other ITX cases we could have used that did offer that access, they were too small for a number of our coolers, so in the end, we only had one reasonable choice: go ATX with the case. That being said, because we unplugged all of our case fans, the cooling setup ended up being fairly similar to what you might find in a cramped ITX case, although we couldn't quite simulate total lack of airflow. That's a serious concern in cases that put the power supply right over the CPU (a design approach we frown upon, by the way). If you have a Small Form Factor case with reasonably-good airflow around the CPU, our results will be fairly representative of what you might achieve with the coolers in this roundup. We know this because we actually tested a few inside an ITX case (the SilverStone RVZ02) and achieved similar results.

While in past reviews, we've used Noctua's excellent NT-H1 Thermal Paste for every contender, after serious deliberation, we decided to use each cooler's factory-supplied thermal paste for this shootout. Here's our reasoning: if you're shopping for $100+ coolers, you're probably not going to mind spending another $8 or so on really good paste. But when you're buying a cooler in the $30-$60 range, it's less likely that such an investment will be appealing. Furthermore, in the competitive mid-range segment, Noctua's coolers are at a disadvantage price-wise in part because they include excellent thermal paste, so we felt they should be given credit for this when other manufacturers may skimp on paste to drop the price a few dollars.

One final note on our test setup: we used an ultra-low-profile RAM kit from second-tier RAM vendor Team in order to give each of our coolers a fighting chance to fit. But this DDR4-3000 kit isn't even capable of hitting its rated speed, which is why we don't recommend it, and instead recommend Corsair every time. Several of our contenders did not fit using the Corsair RAM, and therefore will be receiving technical disqualifications.

To conduct our testing, we kept a thermometer at the base of our case, monitoring it to ensure we maintained a steady 69 °F, plus or minus 0.5 °F. Testing was halted if the ambient temperature varied by more than this amount. We used the application HWMonitor to collect CPU temperatures, selecting the "package" temperature reading, which always reflects the temperature of the hottest core, and we used an Android smartphone app (Sound Meter) to take sound readings.

All right, with that introduction out of the way, it's time to get into the nitty-gritty of our results, starting with a review of installation!

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