Koolance 400A-S TR4 Threadripper CPU Water Block Review

Koolance is a well known name in the mainstream water cooling market but over the years it has paid more attention to the enterprise market. Koolance is however dipping its toe into the Threadripper cooling market, when others aren't yet, with an enthusiast water block for the TR4 socket. Let's see how it stacks up the rest of the current TR4 water blocks.


Koolance 400A-S Flow Rate

Many of our readers asked for flow rate measurements, so we built a quick setup that would work for us. Being a bit slow around here during the holidays, it gave us the opportunity to go back and test all the past Threadripper water blocks we have recently reviewed. Below is a video showcasing the Koolance parts and pieces used to build our flow meter, and then a quick video showing it in action.

Our cooling loop is comprised of all XSPC components: D5 Photon Reservoir/Pump Combo V2 (run at max RPM); RX480 Radiator V3, and XSPC RayStorm TR4 Neo for comparison.

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The Koolance 400A-S performs near the bottom of the pack here, but the flow rate on the 400A-S is still at the 4 liters per minute mark, which is still a lot of coolant moving through our block. Flow rate arguments are like TIM arguments, everyone has their opinion on what they think is bad and good, so your mileage may vary.

Koolance 400A-S Performance

Testing methodology: Our system is started up and allowed to heat-load for no less than 40 minutes for each block. We use Prime95 Small FFT Torture Test for our load. After heat-loading the system, we turn off HWiNFO64, then kill all workers on Prime95 and quickly restart the Small FFT Torture Test. We restart Prime95 because its workload does vary over time. Then we restart HWiNFO64. We then let the test run for 1.5 hours and collect data. Our temperature data is derived with the maximum CPU Package temperature as reported by HWiNFO64 v5.56.

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We will come out and say that after seeing the footprint of the micro-fins on our 400A-S coldplate, we did not expect it to perform this well. We think the 400A-S is doing an very good job here. Worth mentioning, the EK EVO Supremacy was the only water block to actually have a failure during testing as the system hard-locked during one of its temperature testing runs. If you are going to overclock your Threadripper across all 16 cores like we have done here, you do not want to purchase and EK TR4 block in its current design.

As mentioned above, it has been a bit slow around here this week, so we took advantage of the lull and went back and retested all the Threadripper water blocks we have reviewed in the last few months (those reviews are linked below), except for the Bykski block which is no longer have here in our offices. All of the data here is using stock mounting hardware with each water block. We are now using an ASUS ROG STRIX X399-E Gaming motherboard, and a new AMD Threadripper 1950X, so none of the temperature data on this page is comparable with any of the past reviews (except the Swiftech Apogee review which was done this week as well).

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Kyle's Thoughts: The Koolance 400A-S did a much better job than expected after checking its somewhat lacking micro-fin footprint that does not cover fully cover the active dies on the Threadripper. Given its performance, Koolance has some very solid design in its coldplate technology. Koolance was very upfront about telling us that it has simply adapted its Intel coldplate for the Threadripper water block, hence the lacking micro-fin coverage. I think there are several things that Koolance can do to greatly improve its Threadripper water block performance. The first is obvious, it needs to design the micro-fin footprint to fully cover the active Threadripper dies. The second, which may not be obvious, is that it needs to rotate the coldplate micro-channel flow 90 degrees. Currently the flow runs parallel with the length of the dies. I think if Koolance turned that to flow to move across dies side to side, it could pick up some performance there as well. Finally, I think the convex surface of the coldplate is hurting performance too, and it can surely hinder getting a good mating surface between the coldpate and the IHS. The huge size of the Threadripper IHS, and its near perfectly flat surface does not play nicely with convex coldplates.

The Bottom Line

Koolance has built a very good water block for Threadripper overclocking in its CPU-400A-S. While it has some design shortcomings, its 66.9C die temperature under 100% load is far and away from the 85C Threadripper throttling temperature. Koolance's mounting kit is also second to none in the industry and it makes getting a good TIM mating much easier than a lot of other kits that are for sale now. The CPU-400A-S should be for sale on the Koolance site before the end of the year, and its price has not yet been disclosed, but Koolance generally remains competitive with the rest of the market. If Koolance can embrace some of the design changes mentioned above, we think that an updated Koolance Threadripper water block could very possibly wear the performance crown in the TR4 water block market.

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Koolance CPU-400A-S Threadripper Water Block


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