Building a Watercooled PC: Part 1

I’ve been looking forward to writing the post for this project. It may seem that I’m exclusively a Mac user, but my time inside operating systems is probably split 60, 30 and 10 in Mac OS X, Ubuntu and Windows environments, respectively. Mac OS X is obviously my primary platform, but I use the other systems in the area of their strengths. For Ubuntu, that means running my 6.75TB file server and Windows 7 is running some engineering applications and games.

The proportion of the second two OSes will increase dramatically with this project.

Back in September I decided that I wanted to build a super powerful desktop computer running Windows 7, and maybe even Ubuntu. So over the last 4 months I’ve been steadily buying parts to facilitate the goal, and the computer has finally booted. What follows is a description of the process I took, which you can also follow on this [H]ard|Forum thread.

Choosing the Parts

I choose this motherboard on the recommendation of a friend, who has been using the same one for a number of months. In addition, I liked the USB3.0 connectivity, compatibility with Intel’s upcoming 6 core CPUs and triple SLI for the future. So far I have yet to be disappointed.

I choose to go European for my waterblocks. These are from Slovenia, by a company called EK. They are well regarded in the water cooling community for their high quality. These blocks cool the chips on the motherboard surrounding the CPU, and reduce fan requirements for the case to essentially zero.

For the CPU and VGA blocks I chose Germany. AquaComputer makes all of their blocks in house, and ship worldwide. If you ever decide to order from them, try to find a local friend who can split the shipping, because it is a flat rate regardless of order size.

Choosing the graphics card is a super important step for building custom PCs. It has to provide the power to do whatever you want in the near term, but also give you room to grow into whatever application you need later. For those reasons, I bought what, at the time, was the second most powerful graphics card NVIDIA produced (they’ve since released the GTX5xx line that has rendered my choice obsolete). Hearing horror stories about power requirements and temperatures under load, I was relieved that I would be watercooling this chip, which should prevent it from burning through my case.

Speaking of cases, the Corsair Obsidian 700D provides an expansive space to insert every computer related gadget you’d ever need. In fact, the case is so large it hardly fit inside my car. The 700D is the slightly less expensive brother of the super awesome, and similarly sized Obsidian 800D. That case primarily adds a side window and 4 hot swap bays on the front faceplate. I decided on the 700D because I needed that front real estate for my fluid filter. Currently I’m looking for an 800D side window so I can gaze at the work I put into plumbing the internal system.

Not shown are the rest of the parts that are required when building a custom PC.

  • Intel i7 950 Socket 1366 CPU
  • 6GB G.Skill DDR3 RAM
  • 120GB OCZ Vertex 2 SSD
  • OCZ 850W Power Supply
  • 500GB Western Digital Caviar Black 3.5″ Hard drive
  • Generic ASUS DVD-RW

I chose these parts while searching for the best value available at the time. They should provide enough power for any application I might want to run in the upcoming years.

Modding the 700D

Installing the fluid filter into the case required opening a hole in the front aluminum faceplate and steel chassis structure. So I pulled the Dremel from the closet and went at it. It’s a loud, dirty job, but persistence paid off as I slipped the filter into place.

With the aluminum cover in place, the mod is complete.

From the other side, however, the job is slightly less clean. The tolerance was such that I had to use elbow fittings from Koolance to direct the tubing away.

Final Assembly

With the motherboard installed in the case, I ran tubes from the in hole in the case, to the filter, and out through all the blocks on the motherboard. Inside the case the loop runs filter to CPU to graphics card to Northbridge to mosfets and out. I used standard Koolance barbs and fittings on the G1/4 threads installed in each of the blocks. The tubing is 3/8″ ID 0.5″OD tubing from Home Depot. This diameter provides plenty of flow and is easy to connect to the variety of parts in the loop.

For measuring vital stats about in and out temperature as well as flow rate I bought and installed an Aquaero v4.00 from AquaComputer. Connected to it is a collection of sensors including 2 thermocouple water temperature sensors and this high-flow flow meter. It is calibrated to tick at a precise rate for each litre of fluid passing through, and the calculated flow rate is displayed on the Aquaero LCD screen.

I swapped the air cooling heatsink on the GTX470 for the waterblock and installed it into the chassis. It adds weight to the card, but slims the profile down significantly. It is definitely an improvement over the regular air system.

The motherboard blocks were next. The ASUS board used 4 individual heat sinks connected via heat pipe to cool the voltage regulators and associated chips. Those were replaced by 2 mosfet blocks and a single northbridge/southbridge block.

To cool the water flowing through the system requires a radiator and reservoir. I decided to use a now out of date product from Zalman called a Reserator. As shown by the name, this is a combination of reservoir and radiator. Essentially an extruded aluminum cylinder with fins, it has a 2.5L capacity and cools the fluid as it flows from top to bottom. I used two because of the significant heat my computer would be putting out. Both were sourced online from eBay and Kijiji. Interestingly, the Kijiji model was the only one available on the site, and was 10 minutes from where I was at the time. By buying used, I saved approximately $350 combined, which is the cost of a single brand new unit.

Pushing the fluid through these blocks is a generic aquarium pump that was bought primarily for being available at the time I was in the pet store. Rated for 350GPH at zero head, my system produces 50L/hour, which means together the loop has a head of approx. 10-11ft, based on the pump chart. I started with a 24 hour leak test, and the pump has been running perfectly since then.

Not mentioned a lot here is the choice of coolant. I’m using Feser One dielectric fluid instead of water with additives. The Reserators I bought were both encrusted in a blue film as a result of using these additives, and dielectric fluid presents fewer risks to the electrical components in the immediate vicinity. Originally I had 4L in the system, but immediately learned that was not enough when air bubbles were flowing through. I added another 2 and the air bubbles have stopped.


So what have I gained from all this and why bother watercooling in the first place? First, this is a very powerful computer system. In the brief bit of testing I’ve done so far, frame rates in StarCraft 2 hover at about 100 during most of the game, and any other FPS game I’ve played has done so without pause. For gaming and eventual 3D CAD work, it will be a capable machine at least for the next 3 to 4 years. For that power, and the ability to upgrade parts as they require, this has been a great success.

This screenshot I think captures most of the success. I have very little place to go before I reach that magic 7.9 peak. The best part is that with all of this power, the system itself is nearly silent. The case fans I do have are near 35% power to slowly cool the single platter-based drive I have inside, but for the most part I hear nothing. That is the payoff to watercooling. Though getting the parts together and in the same room was rather costly and annoying, once everything is set up there is minimal maintenance and system I’m using should give me room to overclock and upgrade equipment down the road.

For most people, however, watercooling is maximum overkill. In fact, I’m fairly certain watercooling remains popular in maybe 5% of the computer using population. The cost is often a prohibiting factor, but time and energy are key as well. For a custom system like this, you’re looking at spending an additional $400-$500 above whatever you spend on processing parts. Though out of the box systems like Corsair’s H70 can make cooling a CPU more cost effective, you’ll still need to think through every other part to get the results you need. As an engineering graduate, I enjoyed the research into parts as much as putting everything together, so I’m curious what other performance I can get out this setup.

Part 2 I will be sharing more results of experimenting with cooling parameters and overclocking. Would you consider watercooling? Let me know in the comments.

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2 comments on “Building a Watercooled PC: Part 1
  1. Tania says:

    Hi, Thanks for your best Quality computer service. I have so satisfied to your service.
    Tania Tani
    “George Marchelos”

  2. Yyg says:


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