HEATKILLER IV Pro Threadripper Water Block Review

WaterCool.de does not mess around when it comes to water cooling enthusiasts computers for well over a decade now. Many of us have been waiting with bated breath for Watercool's entry into the Threadripper cooling market, and it finally is with the HEATKILLER IV Pro. We compare it to five other water blocks.


Watercool HEATKILLER IV PRO Performance

In December, we went back and retested all our previous Threadripper water blocks on the same motherboard, some CPU, at the same voltage and clock settings, so we could directly compare all of those. That roundup has all the direct links to the individual reviews should you want to look more into those. Below is the video that accompanied that roundup that shows all the blocks.

Flow Rate

You see what we use for testing our water block flow rates in this video and this follow-up video shows the equipment in action.

The Watercool HEATKILLER IV PRO performed very well in terms of flow rate. We would suggest that anything over 4 liters per minute is approaching "excellent."

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TIM Footprint

We have learned a LOT about TIM application and Threadripper, so much that we wanted to share our findings on laying down a good TIM application. If you are going to be building your own Threadripper system, I highly suggest that you give it a watch as it is culmination of our experience of mounting Threadripper hundreds of times.

Below is a look at the flatness of the coldpate. The flatness of this surface is a big deal in terms getting a good mate with the Threadripper IHS (Integrated Heat Spreader). The HEATKILLER IV PRO cold plate shows to be slightly convex. I think this is a win in terms of helping flow off excess TIM. I think being "perfectly" flat is OK as well, but any sort of concave shape to the cold plate is a huge negative in terms of getting a good mate.

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This is a picture of our first mating after it has run a few hours under full load, which certainly allows the TIM to flow under heat and pressure. We did use the method outlined in our TIM Application video. I was very happy with our results here. This sort of footprint tells me two things; we have a good shape on our cold plate, and we have hold-down springs with exhibit a high enough spring rate to facilitate a proper TIM footprint.

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Threadripper Die Temperatures

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

As you can see below, the HEATKILLER IV PRO is the first block to tie the XSPC RayStorm Pro in terms of performance.

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We run Prime95 SmallFFT for 45 minutes and then take the peak temperature seen during that time. Below is a screen shot from out testing should you be interested in where the data was pulled from.

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When I first got the HEATKILLER IV PRO in and took it apart, I truly felt as though it would be the first block that had a chance to unseat XSPC from the Threadripper cooling throne. And while it did not do that, it certainly did just as well as the RayStorm Pro. The bigger micro-fin footprint had me guessing that it might outperform the RayStorm. Had we seen a bit better flow rate from the HEATKILLER I think that certainly would have happened.


We show the first version of this video a few days ago, but I did not like the focus point on the camera, so I re-shot the video you see below with better focus on the flow and slowed it down a bit more. It simply shows an initial start-up on the HEATKILLER and exactly how the coolant flows through the block. However, the original version looked a bit "more dramatic."

The Bottom Line

The Watercool HEATKILLER IV PRO for Threadripper is an excellent piece of enthusiast hardware for AMD Threadripper onwers. We love the design and how it is executed. It is truly German in its approach; form follows function. It is at the high end in terms of cost, like the other best performing TR4 water blocks, and comes in right around $100. When or if it becomes easily available in the US will of course likely dictate a lot of persons' buying decisions, but if you are a Watercool fan, you can feel safe purchasing the HEATKILLER IV PRO and having it shipped. That said, I don't see anyone not being happy with the HEATKILLER IV PRO. And WATERCOOL is known for its excellent customer service, which is something else to keep in mind when buying cooling parts from the EU.

If clear topped water blocks are not your style, Watercool has an all copper version that is bare, and an all copper full nickel plated version.

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WaterCool HEATKILLER IV PRO for Threadripper