Thank you be quiet! for sending us this CPU cooler to review!

I recently reviewed thermal paste for the first time. This was a real challenge, but thankfully I knew I would be reviewing this CPU cooler right afterwards. So after I took my final measurement on that thermal paste review, I installed this new CPU cooler into my PC, and let my son have my old Corsair H100x 240mm AIO (All-in-One) cooler. I had my old cooler front-mounted in my Fractal Design S2 Vision RGB case, but I decided to take advantage of the top-mount optional bracket for this install. It was complicated, but in many ways, quite worth it.

However, while removing that old cooler, the thermal paste stuck to the CPU, and my Ryzen 9 5950X pulled out of the socket, despite the socket's arm being down. In the process of putting it back in, about half of a row of my CPU's pins got bent. I corrected them with a magnifying glass and a razor blade, but unfortunately, it seems like the maximum power draw that I used to get with my old setup went from around 220W to around 200W max. I cannot explain this, but no combination of BIOS settings will let me get those numbers anymore. Unfortunately, this means that direct comparisons of temperature verses power usage is quite difficult, especially since my old cooler is already mounted in another case. I'll still share my data, but I realize it's not perfectly scientific, and that bothers me. Nevertheless, this new CPU cooler is fantastic, and I hope I properly explain why in this review.

For those who are not aware, modern CPUs can use a lot of power that generates a ton of heat. Thirty years ago, a top of the line CPU might use a tiny heat sink, perhaps barely larger than a half dollar. A CPU fan on top was pretty much optional. Twenty years ago, 80mm fans blowing over some aluminum fins sitting on top of the CPU was more than enough. Things started to change as core counts increased, from four to eight and more. My CPU, the Ryzen 9 5950X is no longer top of the line, but it's certainly powerful - and has sixteen cores in it. AMD's latest offers a similar core count, but on the Intel side, they have gone power crazy. My daughter recently got an i9-13900F, and that CPU can easily use over over 300W of power, and will use even more if you let it. Modern CPUs tune performance directly in line with thermal conditions, so the cooler the CPU, the faster it will run. This is why it's essential to manage CPU temperatures with a powerful cooling solution, especially with a high-end CPU like mine or my daughter's.

Many (most?) computers use what you might call direct-contact air coolers. These have several advantages, primarily reliability, cost, and simplicity. The simpler ones resemble coolers of yesteryear, with a simple array of copper and aluminum fins with a fan on top, but the best air coolers combine heat pipes and towers of fins with one or two fans to cool those towers. I've used many of those with great results, but air cooling maxes at around 250W maximum power draw before they simply can't handle any more. To do better, water cooling is pretty much required.

Water cooling consists of a cold plate, which has the hot CPU on one side and flowing water on the other, a pump to keep the water moving, and a radiator to take the hot water and exchange that heat with the cooler air, lowering the temperature of the water as it flows in a loop, cooling off the CPU, which then takes that heat away once again. The constant flow of cold water which warms, then cools off, then flows over the CPU is a very effective heat dissipation mechanism long proven in many applications, including automotive. Water coolers on PCs tend to be limited by the area of the radiator, as well as how quickly that radiator can be cooled. This is why larger radiators, like the 360mm one included in this review product, is so effective. That, on top of the three included fans, means that heat can be removed insanely quickly.

Since water cooling is so effective, hardcore enthusiasts have been building their own water cooling solutions with custom pipes, reservoirs, and pumps for a solid two decades. A good friend of ours had a custom water cooling setup in the mid 2000s, but he didn't maintain it, and his entire setup was destroyed. I don't recall the specifics of his failure (Did it leak? Did it dry up? Was there an algae infestation?) but proper maintenance, not to mention checking how clear your water is and verifying flow and preventing leaks, is critical if you want your hardware to last. For many, the complexity and risks of custom water cooling is not worth the trouble. But, the benefits of water cooling cannot be denied. Enter: the AIO (All-in-One) water cooler.

AIO coolers create a closed-loop system where the manufacturer pre-fills the loop with the required amount of cooling liquid, as well as connecting the radiator, cold plate, and pump in a pre-finished product, They consider the balance between heat dissipation and cooling fan and pump noise levels ahead of time, offering a consistent product to their customers. be quiet! has a reputation for offering high-performance products that prioritize being as quiet as is reasonably possible, and they most certainly succeeded.

This product line might be the only one out there where an AIO cooler puts the pump away from the cold plate. The vast majority place the pump inside of the cold plate housing, making a simpler product with less parts, but the heat of the CPU could impact the longevity of the pump, as heat negatively impact all kinds of electronics. Furthermore, by putting it where it is, you can only hear it pumping by literally putting your ear on the pump - from a few inches away, it's dead silent.

Another practically unheard of feature that this be quiet! model includes is an easy to access fill port, along with included coolant bottle. My old AIO cooler certainly didn't include a spare bottle of additional coolant! This means that, even after the three-year warranty is up, you can add more liquid to hopefully get many more years out of it. They recommend topping it off every two years or so; I never added coolant to my old Corsair and it ran fine for close to five years, so I suspect this cooler could easily last twice that if properly maintained. Very impressive, and shows a commitment to happy customers by respecting that these parts can be investments that last a long time.

It's amazing how quiet the fans are, also. My case includes four Fractal 140mm fans, and they are excellent - Fractal is also known for prioritizing silence in their designs. But while testing this cooler, I came to realize that one of my case fans was plugged into the wrong place! My motherboard has quite a few fan headers, and one of them is meant for a water pump; my bottom case fan was plugged into there on accident, causing it to run at full speed. Once I plugged it into the correct header, my system got really, really quiet. The be quiet! included Light Wings 120mm fans are impressively silent in normal use; if their rated specs are to be believed, these should be virtually inaudible, as anything less than 35dB can barely be heard at all in what is otherwise a silent room. My other fans, in my case and desk, are noticeably louder. Maybe I need to invest in more be quiet! fans!

My old 240mm Corsair AIO water cooler, which has been discontinued for around five years, was known for very good performance, but was much louder than most, with one review I saw measuring over 56dB(A). This be quiet! is in many ways the opposite - with a very large radiator, and flow-optimized low dB fans, this cooler should maintain low temperatures and keep the volume low, also. With Cinebench R23 running, the fans did spin up and get louder, but really not by all that much. My case currently has four case fans (Fractal 140mm), three AIO fans (3x 120mm be quiet!), and three fans on the GPU, and even my cubby, where I keep my computer, has two fans (1x 120mm and 1x 80mm AC Infinity USB fans). Despite all of this, using my trusty RadioShack SPL (Sound Pressure Level) meter, my room with just my PC idling is around 39dB(A). With Cinebench running, it's around 42db(A). Sadly, I wasn't able to measure the old AIO with that one fan fixed, since I didn't discover the issue until long after the old Corsair was removed, but I can say that I could clearly hear my PC spin up loudly when benchmarks kicked in before.

If you recall, I did that Thermal Hero thermal paste review with my old AIO as mentioned in the linked article. That cooler used AMD's default motherboard mounting clips, and when you tightened the screws, the cooler would grip the CPU. If done carefully, it would work well, but the problem is that hook that grabbed onto the default clips was flimsy, and could easily slip off while tightening. This drove me quite crazy when swapping CPU thermal compound. This be quiet! Pure Loop 2 FX uses their own replacement motherboard clips, and they are so, so much better. You unscrew the others, then screw these in their place. Then, when you go to screw down the cold plate to the CPU socket, it has a firm and unmistakable grip on the CPU socket, and just screws right down. You literally cannot mess it up and makes replacing thermal paste so much easier!