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Noise-normalized testing
Most testing is performed with the cooler tied to the default fan curve of the MSI x870E Carbon motherboard, but many of y’all prefer to see tests when the noise levels of coolers are equalized. This is especially important to those of you who prefer silent computers.
We’ll start with the “easiest” of these tests, which runs Cinebench R23 with a stock power limit. On this motherboard, that means the CPU will consume roughly 200W. The Liquid Freezer III Pro 420 achieved the best result we’ve seen yet on this system, with a temperature of only 73.6C – outperforming all of the 360mm AIOs we’ve tested here, and even beating BeQuiet’s Silent Loop 3 420 by 1.4 degrees C.
The next test is a bit harder, with PBO enabled to allow the CPU to use as much power as can be handled, and the cooler handled a whopping 262.3W, on average.
For our last test, we’ve added the heat of a GPU to the mix, which contributes 295W of heat into the PC case. The result of 249.3W is very impressive, outperforming the best 360mm result, with an increased thermal capacity of 16.5W.
Noise levels
We’ve measured noise levels at two points to give you an idea of how the cooler operates when tied to a motherboard’s default fan curve. Our first measurement is when the fans are allowed to run at full speed, their loudest noise levels possible.
In terms of maximum volume, the Liquid Freezer III Pro 420 is quite noisy, at 52.7 dBA. This is the second loudest cooler we’ve tested in the past few years.
Our next acoustic measurement is the cooler’s volume when the CPU consumes 150W. This might be similar to your “worst case” gaming scenarios, especially if PBO is enabled. At 42.4 dBA, it isn’t too loud – but it ain’t quiet by PC standards, either!
PBO Performance – full fan speeds
While some enthusiasts prefer to run coolers at low noise levels, I know a lot of you just want maximum performance. This benchmark lets the fans run at their full speeds to test the full potential of the AIO's cooling potential. Turning on PBO allows AMD’s Ryzen 9 9950X to stretch its legs and guzzle power, pushing the limits of any CPU cooler on the market.
Arctic’s Liquid Freezer III Pro 420 stayed true to its name, cooling over 268W here.
200W thermal benchmarks and noise levels
For the next thermal test, I leave the motherboard settings at their defaults, which results in a power limit of 200W when running Cinebench R23. The performance gap between 420mm and 360mm AIOs shrinks at this power level. While the Liquid Freezer III Pro 420’s result of 73.6 degrees C is the best we have seen thus far, it is only 0.9 degrees lower than the best 360mm AIO we’ve tested.
150W thermal benchmarks and noise levels
For the next thermal test, I’ve set the power limit to 150W.
The story for our 150W results is about the same as our 200W results. The LF3 Pro 420 takes the lead with a relatively cool temperature of only 58.2 degrees C, maintaining a 0.9 degree lead over the best 360mm result we have in this chart.
100W thermal results
Our next test is the “easiest” benchmark featured here, with a workload consuming only 100W. This is a simple test, one that even most mainstream coolers should have no issue dealing with. Results, as expected, are excellent once again, with the average temperature of the CPU measuring 44.6 degrees C, an improvement of 3 degrees CC compared to the best 360mm AIOs we’ve tested.
Conclusion
The 360mm version of Arctic’s Liquid Freezer III Pro is among the best AIOs on the market, and the newer 420mm variant only pushes the bar for cooling performance further, delivering the best temperatures we’ve seen from any AIO when paired with AMD’s Ryzen 9 9950X CPU. If you have the need for this level of cooling and your case has the space for it, the Artic Liquid Freezer III 420 is an excellent cooler and an excellent value – especially if you can find it on sale significantly below its $149 MSRP.
