While stock CPU coolers do serve their intended purpose, they aren't designed for much more – they're good enough, cheap enough, and that's about it. Which is fine for the rank and file office PCs of the world, but as we move up to the realm of high-end desktop processors, we're now talking about chips that can pull 150+ Watts when turboing. Modern, high-end CPUs will essentially will turbo as hard and as long as their cooling systems will allow, making sustaining those clockspeeds critical to getting the best performance out of a system.

As a result, there's a sizable market for higher-performing coolers, offering lower temperatures, less noise, or more often both at the same time. The extra headroom afforded by a good cooler means that advanced users and system builders rarely ever rely on a stock cooler, allowing for a surprisingly diverse and large market for aftermarket coolers – one that become a battleground for manufacturers vying to provide the most efficient cooling solutions at competitive prices.

For today's review, we are taking a look at the Pure Rock 2 FX from one of the industry's better known vendors, the aptly-named and acoustics-focused Be Quiet! One of the company's latest CPU air coolers, the Pure Rock 2 FX is intended to compete in the packed mainstream cooler market as a competitively priced all-rounder. Always a careful balancing act for cooler vendors, the mainstream market lives up to its name by being where the bulk of sales are, but it's also the most competitive segment of the market, with numerous competing vendors all chasing the same market with their own idea of what a well-balanced cooler should be. So a successful cooler needs to stand out from the crowd in some fashion – something that's no easy task when all of them are beholden to the same laws of physics.

So does Be Quiet's latest cooler have that exceptional factor to make it memorable? We will see where the Pure Rock 2 FX stands in this review.

Packaging & Bundle

We received the Pure Rock 2 FX in an elegant black cardboard box, which is typical for most of Be Quiet!’s products. Few details and essential information regarding the cooler are printed on the sides and rear of the box but there is a QR code that leads to detailed information. The box is sturdy enough and the cooler is protected by a combination of cardboard and foam inserts, warranting safe delivery.

Inside the box we found nothing more than the mounting hardware and instructions, making it one of the most frugal bundles we have ever seen. The mounting hardware allows for installation on both currently available Intel (1700 / 1200 / 2066 / 1150 / 1151 / 1155 / 2011(-3)) and AMD (AM5 / AM4) processors.

The Be Quiet! Pure Rock 2 FX CPU Cooler

In terms of size and shape, the Pure Rock 2 FX is a typical tower CPU cooler design, with four 6 mm heatpipes transferring the thermal energy from the base to the sizable fin array. From base to top, the Pure Rock 2 FX is 155 mm (6.1in) tall, making it compatible with standard ATX cases.

A closer inspection reveals that the body of the cooler is asymmetric, with the fin array misaligned in relation to the base of the cooler. This design prevents the cooler from blocking any of the memory slots, allowing RAM modules of any height to be installed and permitting access to the slots at all times. A thicker aluminum cover can be seen at the top of the fin array.

Almost the entirety of the cooler is coated with satin black paint, with the paint job being immaculate. There are round aluminum caps at the end of every heatpipe, also sprayed with the same paint. The paint job will also protect the copper parts of the cooler from oxidation which would severely degrade the appearance of the cooler in the long run. Only the base of the cooler is left unpainted, which needs to come in direct contact with the processor’s integrated heat spreader.

The base of the cooler is small, but not as simplistic as we are used to seeing on typical tower designs. Be Quiet! made the base into a small heatsink of its own, which definitely is not going to make a substantial performance difference but it surely dissipates a little bit of thermal energy, upping the overall performance of the cooler even if by a tiny bit. The heatpipes come into direct contact with the CPU IHS and the cooler comes with a pre-applied pad of thermal paste. Enthusiasts may dislike the notion of pre-applied paste, but it greatly reduces the possibility of beginner errors, which can be plenty within the target group this cooler is aimed at.

One of the most prominent highlights of the Pure Rock 2 FX is the 120 mm Light Wings fan. As its name suggests, it essentially is a Silent Wings series fan with additional LED lighting. Be Quiet! took a different approach regarding the implementation of lighting, keeping the all-black frame and fins and installing an illuminated ring with 18 addressable RGB LEDs on the frame instead. The downside here is that the fan only has an ARGB (5V) connector that needs to be connected to a compatible motherboard header, or the lighting will not function at all. The fan itself has a rifle-bearing engine that lowers noise output significantly and a maximum speed of 2000 RPM.

Testing Methodology

Although the testing of a cooler appears to be a simple task, that could not be much further from the truth. Proper thermal testing cannot be performed with a cooler mounted on a single chip, for multiple reasons. Some of these reasons include the instability of the thermal load and the inability to fully control and or monitor it, as well as the inaccuracy of the chip-integrated sensors. It is also impossible to compare results taken on different chips, let alone entirely different systems, which is a great problem when testing computer coolers, as the hardware changes every several months. Finally, testing a cooler on a typical system prevents the tester from assessing the most vital characteristic of a cooler, its absolute thermal resistance.

The absolute thermal resistance defines the absolute performance of a heatsink by indicating the temperature rise per unit of power, in our case in degrees Celsius per Watt (°C/W). In layman's terms, if the thermal resistance of a heatsink is known, the user can assess the highest possible temperature rise of a chip over ambient by simply multiplying the maximum thermal design power (TDP) rating of the chip with it. Extracting the absolute thermal resistance of a cooler however is no simple task, as the load has to be perfectly even, steady and variable, as the thermal resistance also varies depending on the magnitude of the thermal load. Therefore, even if it would be possible to assess the thermal resistance of a cooler while it is mounted on a working chip, it would not suffice, as a large change of the thermal load can yield much different results.

Appropriate thermal testing requires the creation of a proper testing station and the use of laboratory-grade equipment. Therefore, we created a thermal testing platform with a fully controllable thermal energy source that may be used to test any kind of cooler, regardless of its design and or compatibility. The thermal cartridge inside the core of our testing station can have its power adjusted between 60 W and 340 W, in 2 W increments (and it never throttles). Furthermore, monitoring and logging of the testing process via software minimizes the possibility of human errors during testing. A multifunction data acquisition module (DAQ) is responsible for the automatic or the manual control of the testing equipment, the acquisition of the ambient and the in-core temperatures via PT100 sensors, the logging of the test results and the mathematical extraction of performance figures.

Finally, as noise measurements are a bit tricky, their measurement is being performed manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is being recorded via a laser tachometer. The fans (and pumps, when applicable) are being powered via an adjustable, fanless desktop DC power supply and noise measurements are being taken 1 meter away from the cooler, in a straight line ahead from its fan engine. At this point we should also note that the Decibel scale is logarithmic, which means that roughly every 3 dB(A) the sound pressure doubles. Therefore, the difference of sound pressure between 30 dB(A) and 60 dB(A) is not "twice as much" but nearly a thousand times greater. The table below should help you cross-reference our test results with real-life situations.

The noise floor of our recording equipment is 30.2-30.4 dB(A), which represents a medium-sized room without any active noise sources. All of our acoustic testing takes place during night hours, minimizing the possibility of external disruptions.

*noise levels above this are not suggested for daily use

Testing Results, Maximum Fan Speed

To begin with, we are having a look at the Be Quiet! Pure Rock 2 FX with its stock 120 mm fan running at its maximum speed.

Overall, the performance figures we received from the Pure Rock 2 FX were not far from other similarly-sized products. With an average thermal resistance of 0.1436 °C/W, the Pure Rock 2 FX lands very close to most single-array 120 mm fan tower coolers, such as the Noctua U12A and the Cooler Master EVO 212. It has a relatively steady thermal profile, with the thermal resistance reaching its optimum value with a load of exactly 150 Watts, the design power of this cooler.

Be Quiet!’s main focus is quiet operation, and the Light Wings fan does a fairly good job at it. Although the 37.1 dB(A) that we record with the fan running at its maximum speed is definitely not absolutely quiet, it is a very low figure for a fan running at 2000 RPM. The Light Wings fan is audible at maximum speed but the noise pressure level ought to be tolerable for the vast majority of users, even in a very quiet environment.

Testing Results, Low Fan Speed

In this test we are switching things up a bit, taking a look at the cooler’s performance with the Light Wings fan taken down to half speed.

The reduction of the fan’s speed to 1000 RPM naturally has a negative impact on the thermal performance of the Pure Rock 2 FX cooler, yet that impact is lesser than we anticipated. The average thermal resistance of 0.1812 °C/W is now better than that of most similarly sized CPU coolers, with only the dual fan Noctua NH-U12A and NH-U12S + NA-FK1 coolers managing to outperform it. What gives the Pure Rock 2 FX this performance edge is the speed of the Light Wings fan, which is higher than most other coolers in this test.

Reducing the speed of the Light Wings 120 mm fan down to 1000 RPM makes the Pure Rock 2 FX cooler practically inaudible. With a sound pressure reading of 32.3 dB(A) at one meter, it should be nearly impossible to notice the cooler unless you're in a dead-silent room.

Thermal Resistance VS Sound Pressure Level

During our thermal resistance vs. sound pressure level test, we maintain a steady 100W thermal load and assess the overall performance of the coolers by taking multiple temperatures and sound pressure level readings within the operating range of the stock cooling fans. The result is a graph that depicts the absolute thermal resistance of the cooler in comparison to the noise generated. For both the sound pressure level and absolute thermal resistance readings, lower figures are better.

This chart reveals the standing of the Pure Rock 2 FX cooler against its direct competition. It delivers about the same thermal performance as the Noctua NH-U12S and the SilverStone Argon AR07, yet at either a louder or a quieter noise level respectively. Other similarly sized coolers seem to have lower thermal performance over the same noise levels.

Conclusion

Be Quiet! developed the Pure Rock 2 FX to compete in the mainstream cooler market, building a cooler to serve a good all-rounder with emphasis on quiet operation. Be Quiet was very successful with the technical aspects of this, but actually delivering such a cooler at mainstream prices has proven a bit harder. In practice the cooler's retail price of $53 ends up putting it in competition against some of the more advanced offerings of the most reputable manufacturers on the globe.

The Pure Rock 2 FX CPU cooler from Be Quiet! impresses with its exceptional build quality and striking appearance. With its exceptional build quality and aesthetically pleasing appearance, it certainly makes a strong first impression. The attention to detail and craftsmanship are evident, making it a durable and long-lasting cooling solution. No significant flaws or weak points can be found upon close inspection, and its mechanical strength ensures it will withstand multiple installations and removals without damage. Be Quiet! has certainly set a high standard in this regard.

In terms of design, the Pure Rock 2 FX is a well-conceived product for the target market it is aiming at. By being not too large, heavy, or complex, it allures users who desire an uncomplicated experience and ensured compatibility. It also is cleverly designed so as to leave the RAM slots unhindered, allowing easy access and safeguarding that the cooler can still be used with a full set of RAM modules regardless of their height.

When it comes to raw cooling performance, the Pure Rock 2 FX performs above average but still cannot reach that of the highest-end coolers of comparable size. However, the Pure Rock 2 FX compensates for this with its outstanding acoustic performance. Operating quietly even under heavy load, it ensures a peaceful computing experience, making it an excellent choice for users who prioritize a silent environment.

One aspect where the Pure Rock 2 FX falls slightly short is its price point, as it sits on the slightly expensive side of the spectrum. This is always an area where we as reviewers risk splitting hairs over what amounts to five or ten dollars, but the mainstream market has no shortage of alternatives – or of cost conscientious consumers. To that end, while the higher cost of the Pure Rock 2 FX can be justified by its quality and performance, it will definitely give budget-minded consumers pause. Nonetheless, for those willing to invest a little extra in a premium CPU cooler, the Pure Rock 2 FX offers a compelling all-around package that delivers on its promises.

In summary, the Pure Rock 2 FX CPU cooler from Be Quiet! is an excellent choice for users seeking a reliable, high-quality cooling solution for their PCs. As an all-rounder, the Pure Rock 2 FX impresses with its balance of features. It may not be the absolute best in cooling performance, but its combination of superb build quality, silent operation, and robust thermal handling makes it suitable for a wide range of users. Despite the slightly high $53 price tag, the Pure Rock 2 FX's overall performance and capabilities make it a worthy investment for those in need of a high-quality CPU cooler. Whether you're an advanced user or an enthusiast, the Pure Rock 2 FX is sure to meet your cooling needs without disturbing your ears while adding a touch of elegance to your system.