Many businesses devoted to the design and delivery of liquid cooling systems for PCs were established when the trend of liquid cooling emerged in the 1990’s. One of them was Alphacool, a German business that expanded their product lines to include liquid coolers for use in both industrial and medical applications. Using liquid-based cooling systems into a home PC faced very low adoption rates at the time. The complexity of liquid cooling, which necessitates considerable additional effort and user awareness, possibly was the largest drawback of most products available at the time.

Several years later, the first all-in-one (AIO) liquid cooling systems were released into the market. AIO liquid cooling systems were sealed and ready for installation, making them very attractive to people who sought a liquid-based cooler with an air-based cooler's installation convenience and relative safety. However, AIO solutions are relatively inflexible, and some hardly perform better than high end air-based solutions.

A few years ago, we had our first look at Alphacool’s Eisbaer AIO cooler, which was a hybrid between a sealed liquid cooler and a customizable open loop kit. Although the idea of a modular AIO cooler was new even back then, Alphacool’s Eisbaer was well made and performed very well, making it a rather popular product amongst advanced users and enthusiasts. In today’s review, we are taking a look at the new, upgraded version of the Eisbaer, the Eisbaer Aurora. The most noticeable upgrade is the inclusion of RGB lighting, but Alphacool also performed some quality and practicality upgrades over the previous version.

Packaging & Bundle

The Eisbaer Aurora comes in a dark cardboard box with basic artwork printed on it, focused on a picture of the main block itself. The cooler is well-protected inside a cardboard shell and coated in nylon bags, which offers more than enough shipping protection.

The bundle of the Eisbaer Aurora is frugal, but well-organized. Inside the box, we found only the hardware necessary for the mounting of the cooler and the connection of the fans, as well as installation instructions. The mounting hardware comes in labeled bags and it includes plates for Socket 1700 and TR4 processors.

The Rise Aurora fans are the highlight of the Eisbaer Aurora and perhaps the most important upgrade over the previous version. The obvious upgrade is the inclusion of RGB LED lighting on the hub and frame of the fan. In terms of practical upgrades, the Eiswind fans of the previous version had a maximum top speed of 1700 RPM, whereas the new Rise Aurora fans have a maximum top speed of 2500 RPM and also feature anti-vibration pads.

The Alphacool Eisbaer Aurora 360 CPU Liquid Cooler

Unsurprisingly, the Alphacool Eisbaer Aurora is physically similar to most AIO liquid coolers and, also expectedly, almost identical to the previous Eisbaer version. It looks like any standard AIO liquid cooler, with a radiator and a main block that are connected via two hoses. The major difference that the Alphacool Eisbaer coolers have over the vast majority of AIO liquid coolers on the market is that it is not a sealed kit – the tubing fittings can be undone and there is a connector on one of the hoses. Therefore, although the cooler does come ready for installation out of the box, it actually supports future upgrades by advanced users if deemed necessary.

The radiator of the Eisbaer Aurora may be almost identical visually with the radiators used by many other products. But a closer inspection reveals one major difference: both the channels and fins of the radiator are made out of copper. Alphacool also improved the radiator over the previous version of the Eisbaer by increasing the number of fins and only painting the front side of the radiator’s fins. This way the radiator still looks black (unless observed from the side with a strong light) but also has a much better heat dissipation factor, as the energy does not have to go through the paint to be released to the air. The only issue here is that the higher number of fins suggests higher airflow resistance, and the Rise Aurora fans are not primarily designed with static pressure in mind. The company logo can be seen printed on the sides of the steel frame.

The tubing is another upgrade over the previous version of the Eisbaer. Alphacool used corrugated tubing on the previous version, which is functional and does not kink easily but also is stiff and aesthetically unpleasant. The Eisbaer Aurora has thick rubber (TPV) tubing, which is easy on the eyes and overall better to work with.

The block/pump assembly of the Eisbaer Aurora is tall but not too wide. Much like virtually all pump blocks, it has a plastic body and a copper base. The core difference over nearly every other AIO liquid cooler is that there is a filling port on the top of the assembly, allowing the user to refill and maintain the system. A little window on the side reveals the pump and fluid to the user. This window is not easily visible from the side panel of a case and, even if it was, it is difficult to discern what is going on when the pump is spinning due to its high speed. Nevertheless, Alphacool did install RGB LEDs into the window, as well as on every side of the block, which have the series logo (a bear) etched on them.

Inside the assembly, Alphacool installed one of their own designs that is based on DC-LT Ceramic 12V pumps. It is similar to the design used by the previous series, but the company’s engineers improved it, increasing the maximum flow to 75 l/h (up from 70 l/h) and the head to 0.95 m (up from 0.85 m). Such figures may not be great when compared to large external pumps, yet are impressive for such a small device.

The copper base of the cooler is very smooth and machined down to an amazingly smooth mirror finish. It is coated with an anti-oxidation agent, ensuring it will stay clear even if exposed to the air. The dimensions of the base are just a bit larger than the previous Eisbaer, as Alphacool obviously wanted to cover the latest CPU dies.

The RGBW lighting on the Rise Aurora fans is nothing short of brilliant. There are two rings on the frame, one at the front side of the frame and another one across the middle of it. The hub is also very well and evenly lit. The lighting is untethered from the fan’s engines, meaning that it will not be affected by the speed of the fans and even continue if the fans stop completely. The downside of this design is the number of cables, which can make cable management a bit of a challenge, especially with cases that have little to no room behind the right-side panel.

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

Our maximum speed testing is performed with both the fans and the pump of the kit powered via a 12V DC source. This input voltage should have the pump and fans matching the speed ratings of the manufacturer – however, the Rise Aurora fans were quite a bit slower than their 2500 RPM specification, spinning at 2420 RPM per our tachometer. Regardless, all three fans were consistent, which is what actually matters as it suggests a good quality control.

The thermal performance of the Alphacool Eisbaer Aurora 360 indicates that the cooler lands near the top of similar offerings, slightly bested only by the larger Arctic Cooling Freezer II 420. The average thermal resistance of 0.0697 °C/W just a tiny bit better than that of similarly sized and priced coolers, such as the Corsair H150i Elite and the Cougar Helor 360.

The three Rise Aurora fans that Alphacool supplies with the Eisbaer Aurora are powerful, giving the cooler an advantage on thermal performance but at the cost of acoustics. With all three fans running at their maximum speed, our dB(A) meter recorded 44.3 dB(A), one of the highest figures we have ever recorded while testing an AIO liquid cooler.

Testing Results, Low Fan Speed

Using a PWM voltage regulator, we reduced the speed of the fans manually down to half their rated speed, which is 1250 RPM for the Rise Aurora 120 mm fans. The pump was also connected to the same power source, functioning properly with this supply voltage.

With an average thermal permittance of 0.0784 °C/W, the Alphacool Eisbaer Aurora 360 initially appears to be one of the best AIO liquid coolers that ever went through our labs, matching the performance of the largest AIO cooler, the Arctic Cooling Freezer II 420 and outpacing everything else. This excitement however is short-lived when one remembers that the Rise Aurora fans are quite a bit faster than what most of the competition currently offers.

The noise output of the Alphacool Eisbaer Aurora 360 under these operating conditions is 35.9 dB(A), a figure that is clearly audible. It would probably be comfortable for continuous use in many usage scenarios but it is not ideal for environments where the acoustics are vital, as it would create a continuous source of white noise. The pump itself is entirely silent, without any electromechanical noise coming out of it at any speed.

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 temperature 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 graph reveals that the Alphacool Eisbaer Aurora 360 does outperform most of the competition, yet by a much smaller margin than our thermal testing originally anticipated. The high noise levels of the fans shift the line upwards, closing the gap of thermal performance per sound pressure level. The Corsair H150i Elite even manages to partially outpace the Eisbaer Aurora 360, offering the same thermal performance at lower noise levels.

Conclusion

Alphacool brings the Eisbaer Aurora as an update of the revered – yet now aged – Eibaer AIO liquid cooler that they released roughly six years ago. The Eisbaer was an exceptional cooler at the time of its release, so the new version has very big shoes to fill.

It may seem like the only upgrade is the addition of RGB lighting, but Alphacool knew this would not be enough to compete in today’s market. Their engineers updated practically everything over the previous version, increasing the dimensions of the contact surface, making the radiator denser and better, and changing the corrugated hoses with flexible TPV ones. The fans are also better in terms of mechanical performance, as they have a much higher maximum speed and 0 to 2500 RPM PWM adjustability.

One of the primary selling points of the first Eisbaer liquid cooler was its very low noise levels. The new Rise Aurora fans are more powerful, and although that may have been a necessity to combat the higher resistance of the denser radiator, that makes the Eisbaer Aurora quite a bit louder. The full range speed control does help and it is highly unlikely that most systems will have this cooler’s fans running at a high speed under reasonable circumstances, as a single CPU cannot stress the capacity of such a monstrous cooler even if heavily overclocked. Regardless, when looking at the thermal performance to noise ratio, we can see that the Eisbaer Aurora 360 is not really significantly ahead of its direct competition.

Ever since the first cooler of the series, the expandability of the Eisbaer coolers was one of their main features. The Eisbaer Aurora 360 is very versatile, with a relatively powerful liquid pump and a radiator that can handle very heavy thermal loads, effectively offering expansion options depending on the user’s skill and needs. It has a quick release connector on the tubing for users that want to keep things simple and expand using parts that the company supplies specifically for the Eisbaer series, plus the company has simple tube compression fittings installed on every part that allow the user to completely remove the tubing if necessary. The Alphacool Eisbaer Aurora 360 practically is a standard, divisible liquid cooling kit that is being supplied preassembled and prefilled by the company.

Expanding the Eisbaer Aurora may be a relatively simple process, but the user has to take into account the impact that such an expansion will have on the performance of the system. For example, inserting a GPU block will add both resistance and thermal energy into the system, respectively reducing the flow of the pump and increasing the load on the radiator. The huge radiator of the Eisbaer Aurora 360 can certainly handle it, but every single part added will definitely drive operating temperatures up. In theory, a single loop can be expanded to cover multiple GPU blocks and more than one radiator but, as the pump cannot be upgraded, we advise against the installation of more than three items per system. It is technically possible to add an external pump into the system but that would beat the purpose of having an AIO solution in the first place, as a customized kit would perform better and cost less at this point.

In summary, the Alphacool Eisbaer Aurora 360 is a one-of-a-kind preassembled liquid cooler that combines the convenience of AIO coolers with the upgradability of a custom cooling kit. Its performance is not mind-blowing, but it is comparable to that of the best similarly sized AIO coolers currently out in the market. The retail price of the Alphacool Eisbaer Aurora 360 is its only drawback, as the cooler is currently retailing for over $200. This is quite a bit more than similar products from other reputable manufacturers, leaving Alphacool's marketing team with the less-than-easy task of convincing end users that the high quality and potential expandability of the Alphacool Eisbaer Aurora 360 are worth the premium.