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Unboxing, Overview and Installation

I will right away mention that Watercool did also send a backplate, and I used it in the testing process similar to any other. However, before I could take pictures of it and demonstrate installation (post testing), I had to move to a different place and unfortunately the movers misplaced a small box which contained the backplate among a few other things. As such, please refer to the link on the previous page to take a look at the manufacturer’s images of the backplate and excuse this omission here.

The waterblock arrived in a typical Watercool style packaging- plain white cardboard with color printing on the front. Here we see the company name as well as some select photographs of their products, and there is no other indication of the actual product inside. There is a seal on one side to help keep the contents inside in place, and opening it we see immediately a well written color manual. There is a good amount of detail here, although the English version still has the occasional language barrier effects- nothing that should be a deal breaker though. The manual itself rests on a piece of soft foam which is part of the internal packaging to keep the block itself protected.

Under said foam sheet lies the block itself, in a plastic wrap, and the mounting hardware which comes in vacuum sealed compartments inside a plastic pouch. You get a lot of thermal pads here since Watercool intends you cover not only the VRMs and VRAM modules but a bit more of the power delivery configuration of the GTX 1080 PCB as well. The actual mounting involves screws with a hex head, plastic washers, a bolt to use on the I/O side of the PCB and an Allen key to help use with the screws. No thermal paste provided here so please make a note and get some if you do not have some already.

I got the Ni-Bl version which I personally think is extremely gorgeous. This has a nickel plated copper cold plate, an acrylic top with a black aluminum cover over the top on areas that just cover the PCB and not show the coolant under. There is a Heatkiller IV etch on the front, as opposed to the Watercool company name itself, and this is more indication of a possible brand identity crisis for Watercool where they and their products are more commonly referred to as Heatkiller instead.

The nickel plating is very well done, Watercool outsources this to a professional plating company and the end result is a nicely buffed cold plate with a mirror finish and no machining marks.

The Heatkiller IV (GPU and CPU blocks alike) line has split central inlet flow for the coolant and this there is a preferred inlet and outlet for the ports. This block has four threaded BSP G1/4″ ports, and comes with two stop plugs to use with the spare ports. It, however, does not come with an Allen key to loosen/tighten the ports and I had to find my own to even remove them. I encourage Watercool to supply an Allen key if they wish to use these plugs, or move to ones with a flat slit in the middle instead. The ports are not marked as far as designated inlet or outlet goes, and Watercool says you will lose perhaps a few % in performance if you went with the right side ports (as seen from the front) as inlet instead of the left side ports. In practice, you would want to use a left port for inlet if you can.

Disassembly of the block is fairly simple if you have a good set of precision driver bits. The aluminum top cover and the acrylic top are both held in place by two separate set of screws, and we can see that the top too extends the length of the PCB here. It has a polish as well, although this having been done post testing has had some distilled water remnants still.

There are several microchannels cut into the cold plate directly above the GPU itself, with a thick stainless steel jetplate for the split central inlet flow mentioned above. This has the benefit of lowering liquid flow restriction and increasing thermal dissipation over those that do serial flow, so I expect to see such blocks generally outperform the latter. The I/O manifold is made of POM and is held in place with one large O-ring as opposed to two for the inlet and outlet separately.

On the right side of the block (near the PCI-E connectors) is an opening where you can put in an optional accessory- an LED strip. Watercool sells these in single color versions (white, red etc) and this leaves an LED connector coming off the block that then hooks into the LED header on the GPU PCB itself. Since the GTX 1080 reference PCB has no RGB LED header, you can not simply use an RGB LED strip here either, but Watercool has made RGB LED strips part of their non-reference PCB waterblocks (such as for the EVGA FTW).


Put back together, and with some colored coolant in, we get to see the block in a more informative way which helps illustrate the nature of coolant flow inside as well- enter from the left port (how I went about it, anyway), cool some of the VRAM modules, split at the GPU core into two parallel streams, have one stream cool the remaining VRAM modules and the other cool the VRMs, both streams combine near the right exit port and leave the block.

For a quick installation demo, I used the block as-is from the previous work with the colored coolant inside. Installing this is very simple, as long as you take the time and read the manual properly. There are a lot of thermal pads in use here, so you will need to use a pair of shears/scissors to cut them to length and place them on the correct components. Watercool does provide more than you need so don’t worry if you cut a pad down longer than needed.

Once all the thermal pads are placed (making sure to have removed the plastic covers on both sides), apply thermal paste on the GPU and place the block on top aligning the holes in the PCB with the stamped, threaded inserts in the block cold plate. Alternatively, you can have the block resting with the cold plate facing up and maneuver the PCB on top if that is easier for you.

Use the provided screws, washers, bolt and Allen key to secure the block to the PCB. Begin with the four around the GPU in a diagnonal manner and then go outwards. I suggest not tightening each down immediately, and instead loosely securing all before then tightening them all to where you feel resistance and then a quarter turn more- no more than that. Check and make sure the PCB is not bent or warped in any place due to uneven pressure.

For those curious, the EVGA stock backplate works with the Watercool block and a combination of EVGA backplate screws and Watercool screws.

I am going to not demonstrate TIM spread for any cooler/block that does not come with TIM henceforth, so I will just show the contact that the thermal pads had instead. The Heatkiller IV block made good contact with the VRAM modules as well as the VRMs, with the easiest to notice contact done with the larger VRAM modules as seen above.

Overall, installation is among the easiest I have done. Even with the Watercool backplate involved, all it took was another five minutes in total, and it came with it’s own detailed manual as well.

Let’s now see how it performs beginning with liquid flow restriction on the next page.


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