Asetek 645LT 92MM AIO Liquid Cooler Review: SFF’s Best Friend

One of our most requested reviews from our Sliger SM560 build is for the unique 92mm AIO liquid cooler we used, the Asetek 645LT. Asetek made this unit specifically for small form factor (SFF) computer builds and they used their expertise in the high-end desktop AIO market to design and create what may be consider the best cooling solution for processors in such small environments. Let’s see if it is!

About Asetek

For those who aren’t aware, Asetek is king of all-in-one liquid cooling. They invented the technology and are the OEM for all the popular sealed liquid cooling units from EVGA, Corsair, NZXT, etc. When the SFF (small form factor) community needed a miniscule yet powerful cooling solution for ultra-compact cases such as the Dan Case A4-SFX and Sliger SM560, Asetek answered the call.

Unboxing & Overview

For our review, we received a special packaging in the form of a metal box with the Asetek logo. It is so unique and special, we had to share it!

Peering inside the box, we see the 645LT in its plastic wrapping. There is also a Noctua fan hiding in the back. Note that not all distributors of the 645LT include a Noctua 92mm cooling fan.

Here are the contents of our review unit. The 645LT, a Noctua NF-A9x14 PWM fan, both Intel and AMD mounting hardware and various screws and washers which are used to mount the AIO in your case. The 645LT already has thermal paste applied to the pump block, saving you a step when it comes to installation.

The 645LT uses Asetek’s latest pump (6th Gen) which has a pump speed of 2800 RPM. Tubing length is 250mm and the tubes have 90-degree connectors coming out of both the radiator and pump block. There is support for one 92mm fan up to 14mm thickness, the Noctua NF-A9x14 PWM is an ideal match.

The 645LT is of course compatible with nearly all modern CPU sockets including Intel: LGA 115x,1366, 2011, 2011-3, 2066 and AMD: AM4.

Asetek 645LT vs. 545LC

The 645LT was introduced to replace the original Asetek 92mm AIO, the 545LC. The dimensions of the 645LT remain the same as the previous generation unit. Major differences include the use of Astek’s new 6th generation pump on the 645LT. Noise is reduced by the inclusion of noise reduction foam in the pump cap.

Finally, the tubing remains unsleeved and is greatly improved; there are now 90-degree angled bends coming out of the pump block which allow for easier installation in tight spaces. The tubing is also longer, again making it easier to install.

Performance & Noise

On our stock Intel Core-i7 8700K, our idle temperatures hovered around 37C, this is with about 16 apps open in Windows 10 with 15GB of 32GB of system memory in use. Under load our temperatures increased to as high as 75C. These temperatures were obtained from our Sliger SM560 build.

The Asetek 645LT, seen in our Sliger SM560 build.

Pump noise is relatively minimal on this unit, especially given that our computer is within arm’s reach of our keyboard, we were very impressed with the noise levels. They are much better than the older Astek units we have used in years past and emphasize the fact that Asetek continues to improve their product with each new generation. Under load, the increased pump and fan noise is certainly noticeable but not bothersome and if you are gaming and using headphones or speakers, it won’t be a bother at all.

Conclusion

The Asetek 645LT is a fantastic liquid cooling unit and delivers powerful cooling performance in an incredibly tiny package. Leave it to Asetek to make the perfect SFF liquid cooling solution, the 645LT works extremely well in tiny cases such as the Dan Case A4-SFX where space is at an absolute premium and it’s incredibly difficult to effective cool high TDP processors such as the Intel Core i7-8700K and Intel Core i9-9900K.

We highly recommend this unit; we’ve tested it for over a month with no problems whatsoever. Asetek is a proven company that builds solid, well-made products and the 645LT is no exception!