INTRODUCTION

    Even though AIO liquid CPU coolers have long since reached a bottleneck in terms of cooling efficiency most consumers still prefer them over regular CPU air coolers and well, I get the why. AIO liquid CPU coolers are easier to install compared to large CPU air coolers, offer zero clearance issues with motherboard components and RAM, produce higher cooling performance compared to the majority of air coolers out there and for the most part they look a lot better. be quiet! recently announced their new Silent Loop 3 line of AIO Liquid CPU coolers and for the past 2 weeks I've been testing the 420mm variant.

    We are the German premium brand manufacturer of quiet hardware components for gaming, workstations and desktop PCs. Since our foundation in 2001, we are proud to have more than 20 years of experience in the industry. Our goal from the very beginning has been to develop products of the highest quality that are not only quiet, but also extremely powerful. With a wide range of power supplies, PC cases, water and air coolers and fans, we have established ourselves as a leading manufacturer in this field.

    This time over be quiet! has made their latest Silent Loop 3 AIO available in 240/360/420mm sizes (black in color) in order to cover a larger segment of the market. The 420mm sized model consists by an 457mm long, 140mm wide and 27mm thick aluminum & copper radiator, three Silent Wings 4 140mm PWM high-speed fans (6 pole motor / 1900RPM / 78.4CFM / 2.36mmH2O / 29.3dBA), 400mm long braided tubes, high-speed 3500RPM pump (3 chamber design with 6 pole motor) with ARGB LEDs on top (compatible with all 3pin 5V RGB sync technologies) and an extra-large (1800mm2 fin area) nickel plated cooling block/coldplate (for increased cooling efficiency). As for warranty be quiet! covers the entire Silent Loop 3 line with a 3-year limited one.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

Typically, at the front of the box we find a large product picture, company logo and the product name.

The specifications table is printed at the bottom of the box.

At the rear we find 4 product pictures used to showcase the main features in 2 languages.

Again, the AIO and its bundle are all placed inside a formed piece of cardboard.

Along with the main body of the Silent Loop 3 420mm and its 3 fans inside the box be quiet! has also placed a y-fan splitter, 3 cable ties, thermal paste tube, warranty information, user manual, Intel backplate and all the bits and pieces required to mount the AIO onto Intel LGA 1150/1151/1155/1200/1700/1851 and AMD AM5/AM4/TR5/TR4 motherboards.

THE SILENT LOOP 3 420MM

Again, just like most AIO models in the market the Silent Loop 3 420mm doesn't really stand out, not at first glance.

The radiator is 27mm thick, so this is quite standard.

FPI (fins per inch) for this 420mm radiator is 20.

Using 400mm long braided tubes with such a large AIO may not be the best choice (420-450mm would be better when used in very large PC cases).

The pump/coldplate combo has the be quiet! logo on top just over numerous ARGB LEDs.

The waterblock be quiet! has used is easily among the largest ones around (since this is a TR4 compatible AIO it does make sense).

Here you can see an exposed view of the pump/waterblock (marketing material).

With a maximum speed of 1900RPM, 78.4CFM airflow and 2.36mmH2O pressure the new Silent Wings 4 PWM fans should offer good performance.

After mounting all 3 fans the thickness of the Silent Loop 3 420mm increases to 52mm.

INSTALLATION

Installation is very easy so after mounting the radiator you just need to mount the rear backplate and secure it with the bundled screws as seen above.

After that you will need to mount the two brackets which I initially mounted wrong since I thought that the bottom capacitors would interfere.

Once the brackets are properly mounted you can secure the pump/waterblock with the two attached screws.

Since the fans don't feature A/RGB lighting just the top of the pump does and well, it looks nice (short clip is available both on TikTok and YouTube).

TEST BED

TESTING METHODOLOGY

   Testing complete water cooling kits or individual radiators is no different than testing CPU Coolers and since we want all of you to be able to compare similar products, we created new and separate charts (you can still cross-compare results however since we are using the same test rig). So once again single (120/140mm) watercooling solutions are tested with the radiator mounted at the rear of our test rig while dual/triple/quad (240/260/280/360/420/480/560mm) solutions with the radiator mounted at the top. For the dBA tests complete water cooling kits or radiators with bundled fans are measured both while on idle mode or with the fan controller in the minimum setting and while on extreme load or with the fan controller all the way to the highest possible setting (PWM fans do that on their own without our intervention). Every single test takes place in a temperature controlled room of 23 degrees Celsius Ambient Temp with the help of two AC units placed diagonally inside the room and as for thermal paste I’m using the NT-H2 by Noctua. Finally, much like when testing CPU Coolers, it's very important to point out that just because a water cooling kit (or a AIO) outperforms another when tested with our test rig (when we test complete water cooling kits) that does not necessarily mean that the same performance differences will apply 100% for other CPU models and in other situations (such as different ambient temps and system configurations).

     To successfully record the load temperatures, we use the latest OCCT application for around 6-10 minutes to push the processor to its limits and after that is done and the temperatures are recorded, we wait for about 10-20 minutes for the CPU to cool down and record idle temperatures. This is done to allow time for the thermal conductive material to achieve the optimal performance level. Same procedure is then repeated with the Passmark BurnIn Test as a failsafe just in case the OCCT results are wrong. This procedure takes a lot more time than the usual peltier/thermometer tests, but this way not only can we deliver real world results to our readers based on real CPUs, but we can also triple check the results using a variety of programs. Last but not least the temperatures were recorded using the latest version of AIDA64 while noise level tests (when fans exist in the bundle) are performed using a high precision ExTech HD600 Decibel Meter placed about 10-15cm above the radiator. Still although the same testing procedure applies to all units do take into consideration that unlike the official numbers which are measured in special noise isolated labs with just the fans here, we also have both the rest of the cooler and the rest of the system (although all system fans are turned off when recording noise levels).

* Since some manufacturers have ceased support for the Intel LGA 2011-3 platform, for such coolers, I’ll be using the Ryzen 7900X / ASRock X670E test rig.
** After high demand since September 2024 I’ll be including average temperatures in my AMD Ryzen 9 7900Χ/Χ670Ε charts (under light load such as Internet browsing and Office use).
*** Since November 2024 I swapped test systems with the Intel Core Ultra 285K (same methodology as with the AMD Ryzen 9 7900X).

TEST RESULTS

CONCLUSION

    What else is there to say about the Silent Loop 3 420mm that you haven’t already seen in this review and of course the charts? CPU cooling performance is very good (alas I was expecting slightly better cooling efficiency – not so much for surrounding components since the pump/coldplate combo doesn’t come with a fan), noise levels are low and as for looks the lack of A/RGB lighting for the fans goes unnoticed, for the most part (still it would be nice to have). Having a very large coldplate is also a good thing for all the latest CPUs and so I do hope more manufacturers follow suit (for smaller CPUs however I don’t quite know, cooling efficiency could be higher with a smaller coldplate).

    The Silent Loop 3 420mm already counts 1 month in the global market and currently retails for 189.62Euros inside the USA (Amazon.com) and for 171.45Euros inside the EU (Amazon.de) a price tag which is more or less what I’d expect for a high-end 420mm AIO model. Bottom line if you’re out in the market for a top AIO model and your case is big enough to fit 420mm models the Silent Loop 3 420mm by be quiet! was made for you and that’s why it gets the Golden Award.

PROS

- Build Quality
- Very Good Cooling Efficiency
- Noise Levels
- Motherboard Compatibility
- Extra Large Coldplate
- ARGB Top (Compatible With RGB Sync Technologies)
- Up to Six 140mm Fans in Push & Pull

CONS

- Size (For Some)
- Plain Fans (No A/RGB Lighting)