Build It: Three Water-Cooling Techniques Detailed and Constructed

Maximum PC Staff

Can an off-the-shelf cooling loop out-cool a custom-built system?

I’m taking a standard midrange computer with a Core-i7 930 CPU (stock speed: 2.8GHz) and clocking it up to 4GHz. That’ll up my CPU’s heat output, and I’ll need better cooling. Water-cooling can be quieter and more effective than air, but isn’t necessarily cheap or easy to install.

How much time and money do you need to spend to get good cooling? To answer this question, I’m testing three build options: a basic off-the-shelf liquid-cooling loop (Corsair’s H70), an all-inclusive Swiftech DIY kit, and finally, a custom-built water-cooling setup of my own configuration. How can I get the best performance for the least money, time, and aggravation?


Total Without Cooler: $1,419

Cooling Option 1

  • Off-the-Shelf Corsair Cooling Hydro H70 all-in-one liquid cooler $110

Cooling Option 2

Cooling Option 3

Total: $558

Choices in Water-Cooling

Part of the problem with water-cooling (as opposed to, say, conventional air-cooling) is the depth of the market. At the shallow end are closed-loop systems like Corsair’s H70, which you just slap into your case and go. Next come DIY kits, like Swiftech’s H20-320-EDGE, which include everything you need to water-cool your CPU—pump/reservoir/radiator unit, tubes, fittings, water block, and fluid—but require some assembly. Finally, the completely custom option: All you have to do is figure out the best radiator, pump, reservoir, fluid, tubes, fittings, and water block, then put them all together. Making sense of this last option has long been a source of pride and true geek-cred.

Herein lies the real challenge of this month’s build: Given the widespread availability of off-the-shelf cooling loops and systems, from entry-level to boutique, does building a custom water-cooling loop even make sense these days? We’re gonna find out.

Option 1: Corsair Hydro H710 All-in-One

Installing an all-in-one liquid-cooling kit like Corsair’s Hydro H70 is about as easy as water-cooling is ever going to get. It’s a great first step for those looking to push beyond the limitations of air, but who are terrified of the destruction wrought by the unintended marriage of liquid and active electronics.

Thankfully, Cooler Master’s HAF X comes with a 14cm rear exhaust fan by default, but also has mounting holes for 12cm fans—perfect for the fans on my Corsair H70.

You can’t hand-tighten it, but the mounting mechanism for Corsair’s H70 is one of the easiest to use of the many water-cooling blocks we’ve installed. Don’t forget the thermal paste!

In attaching the H70 to the rear of the case, I first removed the 14cm rear exhaust fan that ships with the HAF X—the H70’s radiator and fans mount to that space, which also includes 12cm mounting holes. I arranged the device’s two 2,000rpm fans in a push-pull format. I set up the exterior fan to deliver cool air into the radiator from outside the chassis while its companion, the interior fan, was tasked with accelerating the process by sucking this air through the radiator as fast as possible.

The H70, like many mainstream all-in-one setups, includes a pump built right into the cooler’s CPU water block. After adding thermal paste to the CPU itself, I fit the water block underneath its retention mechanism, and then twisted a screwdriver a few times on each of the four screws that run through the retention mechanism into a backplane behind the motherboard.

Tightening the screw on a water block is an art: Make sure you’re applying enough force to keep the water block firmly adhered to the CPU, but not enough that you’re hurting your motherboard.

To lock the water block into place, I twisted it ever-so-slightly to the left so that notches built into its frame fell underneath the corresponding locking elements on the retention mechanism. I then tightened the retention mechanism into the board by turning its four screws (gently) until I could twist no longer—a tight connection is important, but you should never force it. I then connected the fan cables to the CPU fan header and the pump cable to another 3-pin header on the motherboard.

In my tests, the H70 performed adequately in its cooling benchmarks, drawing an idle temperature of 35.3 C on our 4GHz overclocked system. Kicking the system up to 100 percent CPU use across all four cores brought temperatures to an average of 74.3 C, with a maximum average recorded temperature of 75.5 C. Not too shabby… but not great, either.

If you want the advantages of water-cooling without the huge footprint or mess, a single-radiator all-in-one setup causes minimal disruption.

Opinions vary on whether to install your radiator fans as intake or exhaust. We prefer intake.

Option 2: Swiftech H20-320 Edge All-in-One

To say that Swiftech’s H20-320 Edge liquid-cooling system is an all-in-one kit is a bit of a misnomer. This radiator/block combination delicately straddles the line between a true all-in-one design and a completely customized build-it. But because of that, it’s an excellent intermediate step in the liquid education process. It doesn’t force newbies to configure a full setup all on their own, but it still makes them cut tubes, fit hoses, and—gasp—pour their own liquid.

The Radiator

The three-bay radiator that comes with the kit is actually one of Swiftech’s MCR320-Drive reservoirs, which combines a small reservoir, three-fan radiator, and a Swiftech MCP35X pump into a single, cohesive unit. Its two fill ports sit on the opposite side of the MCR320’s two 1/4-inch holes used to transfer liquid to and from the contraption. Twisting on the barbs that attach to the included 1/2-inch-diameter tubing (inside diameter, that is) is as easy as it sounds. Installing the radiator was not.

Because of peculiarities with the HAF-X’s fan holes, the screws included with the MCR320-Drive were not long enough to successfully penetrate fan, case, and radiator. In this instance, I had to use smaller (included) screws to attach the bottom of the three included 2,000rpm fans to the radiator, and turn to plastic pins (also included) to attach the fans’ tops to the steel of the chassis.

The Water Block

The specifics of attaching a water block to a CPU vary with each product, but all—including Swiftech’s Apogee XTL, which was included with the kit—tend to follow a common installation process: You hold a backplane to the rear of the motherboard and tiny threads extend out of the four holes surrounding the CPU socket. Dab and spread some thermal paste on the CPU, gently set the water block on top of the CPU, align the screws with the threads, and twist screws (thumbscrews, in this case) to create a tight pairing between the two without breaking anything.

Thumbscrews with springs make water-block installations easy: Hand-tighten until you can tighten no more.

Attaching the 1/2-inch tubing came next. I started by attaching two tubes to the radiator’s input and output, then matched the output of the radiator with the input of the water block and vice versa. It’s as easy as pushing the tubes onto the matching barbs I previously installed into the radiator and CPU water block. One caveat here: I also checked to make sure that the four matching clamps—one per tube/barb connection, used to hold the tube close to the barb and prevent leaks—were already ringing the tube. Once each tube was in place, I tightened the clamp over the matching indentation in the barbs. For cheaper, plastic clamps, you have to mash its two halves together until they click-lock. In this case, tightening the clamp involved tightening the tiny screw that, itself, pressed the clamp closer and closer against the tube and barb.

Secret Tip: When you’re attaching your clamps to the tubing, make sure you align the screws so you can easily tighten them if you’re, say, trying to do this all inside of your case.

The Water

You can’t have water-cooling without the water. In the case of Swiftech’s all-in-one, that comes in the form of a bottle of green additive that gets mixed with a liter of distilled water—distilled, because the minerals and ions found in tap water would corrode the kit’s parts. After I mixed this concoction, I filled the system by priming the pump, a delicate process helped out by the Antec Digital PC Power Tester I happened to have on-hand. This allowed me to start the power to my power supply without booting the rest of the motherboard/system. When you’re priming a pump, the last thing you want to subject your poor motherboard to is three-second bursts of on, off, on, off, on—you get the picture.

Now’s a good time to remind you that the first real act of filling your fluid loop should happen outside of your case.

Priming a pump involves getting it to the point where you’ve created a continuous loop of liquid: Water is passing around your setup with nary an air bubble in sight. To get this to happen with Swiftech’s kit, I filled the reservoir, tilted the case about 30 degrees toward the “pump” side, flipped on just the power supply, and let the pump run for a few seconds. I then flipped the power supply off, refilled the reservoir to make up for all the coolant now slowly making its way through the loop, and repeated the process until the tubes were full of sweet, continuous fluid.

And that’s it! Temperatures on the Swiftech kit hit an average of 36.5 C degrees for the overclocked system when idle, and an average of 68 C on full burn (with a maximum average recorded heat of 69.8 C degrees).

Swiftech’s all-in-one H20-320-EDGE strikes a middle ground between the barely there H70 and our enormous custom loop.

Make sure your tubes are clamped down. Priming the pump, which is attached to the radiator, involves tilting the whole case forward.

Build 3: The Custom Build

Big thanks to the following companies for providing the water-cooling parts used in this build: Corsair (Corsair H70); Swiftech (H20-320-EDGE system, MCP655 pump); Koolance (Quick Disconnect parts, CPU-370 water block); and especially (everything else).

After testing a few water blocks on an identical water-cooling setup (Swiftech’s), I determined that Koolance’s brand-new CPU-370 water block was dishing out the lowest system temperatures. I used this as the cooling basis for my custom-build system, and it was the first thing to go atop the motherboard—using the same installation process as the coolers previously mentioned, of course.

Connecting the Parts

Next into the case went the reservoir. Since I’m from Ohio, and we do love our tornados in the Midwest, I was hoping to evoke a similar look and feel for my system’s insides by using EK’s Multioption RES X2-400 Advanced Reservoir—essentially, a giant vertical cylinder—to house all the liquid that was going to get sucked out into the tubing loop by one of Swiftech’s MCP655 pumps (317 gallons per hour to the MCP35X’s 285). I slapped this into the corner of the case, attached some of Koolance’s amazing Quick Disconnect fittings to connect it (and all the parts in the system—see sidebar), and ran a single small tube from the bottom of the reservoir to the top of the pump (mounted sideways next to the reservoir) to wedge both components into place against the case’s frame. Yes, wedged: the mounting clips for the reservoir didn’t work at all.

If you’re going to use the same Koolance Quick Disconnects that we did, make sure the drilling of the water block’s 1/4-inch holes are compatibly placed.

Figuring that more reservoir space is a positive thing, I did my best to sandwich XSPC’s 12.4x6.3x40-centimeter RX360 radiator into the top of the HAF-X. Using the same tricks to mount the Swiftech all-in-one, I just barely got this behemoth of a radiator to stay in place. I opted to use three Scythe Gentle Typhoon fans to connect the reservoir to the chassis—1,850rpm fans, mind you—in an effort to balance heavy cooling with relative quiet.

I used 1/2-inch Tygon tubing to finish connecting the various parts in this flow order: reservoir, to pump, to radiator, to CPU, to reservoir. This, in theory, allows the chilliest possible water to flow into the CPU (as pumps tend to add a little bit of heat into the equation during pumping).

Fluid going… vertical? It has to happen at some point, because you always want your pump to be one of the lowest elements in the entire loop—good luck priming the darn thing otherwise.

Koolance’s Quick Disconnects meant we could literally remove and connect hoses at-will, fluid-filled or otherwise.

Priming the System

I primed the system a little differently than before, as the super-huge reservoir (nearly extending from the bottom of the case to the bottom of the radiator) made it unnecessary to do much priming at all. I poured my mixture of Swiftech additive and distilled water into the acrylic tube of a reservoir—to the brim—then sealed the lid and turned the pump on. It took but one refilling of the reservoir (to less than the brim this time, just to be on the safe side) to get the system up and running.

My custom overclocked system reached 36.5 C when idle and 71 C on full throttle, with an average maximum temperature of 72.3 C. Though this is higher than the Swiftech’s average, it isn’t necessarily a loss—remember, I swapped out quieter fans on the radiator. While Swiftech’s default all-in-one might win the day in the temperature race by a scant few degrees, there is no way I would ever put a system with fans like that anywhere near my office, living room, or soundproof panic room. It’s just too loud.

My custom build was as cool in temperature as it was in design, purring like a kitten while delivering excellent thermals—for all those times I’ll be running my Intel Core i7-930 processor at 4GHz across all cores. It’s pricey, but it’s far better looking and sounding than the Swiftech system.

This double-thick XSPC radiator needs a lot of room. Fortunately, the HAF X case has plenty of room to spare.

The Greatest Water-Cooling Purchase Ever

They’re expensive, but Koolance’s Quick Disconnects are hands-down the greatest invention that the water-cooling world has ever produced. Here’s why.

The old way of adding and adjusting parts in your rig was as follows: You connect tubes using the ever-annoying, leak-prone plastic or steel hose clamps. They’re hard to get to with fingers or a screwdriver and even harder to take off. Modifying any part in the loop you’ve built forces you to drain the entire setup, which is as annoying as it is time-consuming.

Koolance’s Quick Disconnect parts are huge life- and time-savers.

With Koolance’s Quick Disconnects, however, the male and female connectors effectively block every last bit of fluid from ever leaking out of its attached part, period. You can disconnect a tube that’s completely full of fluid without spilling a drop; you can rip out a radiator, drain it on its own, and install a brand-new device with all the rest of the liquid sitting right there in your system.

And clamps? Pshaw. To connect the male and female parts, you just push one into the other and give it a little twist. Disconnecting is as easy as giving the male connector a little twist in the opposite direction and pulling it out. When I say that these simple little accessories saved hours of time and square feet of wet, stained carpet, I kid you not. I will never go back to barbs and clamps again.

The Five Most Important Facts About DIY Water-Cooling

Are those parts going to bring you a chillier system?

If you don’t have the skill or time to futz with building your own custom water-cooling setup, then hopefully our tests have shown you that all-in-ones can provide a competitive alternative in both cooling and price. This said, you can tap into considerable builder’s satisfaction through the custom route. For some of us, this is the true joy of water-cooling. There are a crap-ton of parts that independently contribute to the success or failure of a given system.

I tested way more parts than I had space to mention here, but learned many important lessons. Here’s what to watch out for to ensure that you have the best chance of reaching Maximum Chill if you want to try and beat the prebuilt kits at their own games:

1. Tubing is Everything

3/8-inch-diameter tubes spiked our temperatures on 100 percent CPU use to an average of 81 C and a maximum of 83.5 C. The same cooling setup using 1/2-inch tubing hit an average of 73 C with a maximum of 75.25 C. The more fluid you can move over your heat exchanger, the cooler the average temperature that fluid will be—that’s why 1/2-inch tubing wins.

2. Good Water Blocks Matter

We saw an average variance of 7 degrees on our 100 percent CPU burn tests on the three different top-tier water blocks we tested (EKWaterBlocks’ Supreme HF, Swiftech’s Apogee XTL, and Koolance’s CPU-370), with the maximum tested temperature varying by around 4 degrees. The quality of the water block will impact your performance, but there’s no quick way to spot what construction characteristics will make for an excellent block. Do your homework; research others’ experiences before you buy!

3. Don’t Double Up

One radiator might do a pretty good job cooling, but two radiators (with fans, of course) would do even better, right? Wrong. We saw just a 3- to 4-degree difference on our average and maximum “full burn” temperatures when strapping another 14cm radiator into the loop of our Swiftech H20-320 setup. The hassle—and the ugliness of having a radiator latched onto your case’s butt—just isn’t worth it. Note that while this is true for our CPU-only setup, larger loops (cooling multiple CPUs or GPUs) can benefit from more radiators—to a point.

4. Bigger isn’t Better

Just because a radiator is huge doesn’t mean that it’s going to bring your system to the Ice Age. The statistic to pay attention to on a radiator is the number of fins it packs per inch of space: Radiators with higher FPI levels benefit most from fans that pump a lot of air through their frames, whereas radiators with lower FPI levels (like the XSPC RX360) are really geared toward lower-rpm fans—you just won’t see as big a cooling difference if your fans go full-blast on an eight-FPI radiator.

5. F%@& Fluid

If you buy expensive fluid expecting it to be the elixir of the gods for your water-cooling setup, you’ll be disappointed. In our tests, $2 distilled water worked just as well as the most expensive water-cooling fluid we could find—$50 a bottle.


Swiftech H20-X20
Custom Rig
Overclocked Frequency (idle)
Overclocked Average Idle Temperature 35.25 C
36.5 C
36.5 C
Overclocked Frequency (100% use) 3,990MHz
Overclocked Average Core Temperature (100% use) 74.25 C
68 C
71 C
Overclocked Maximum Average Core Temperature (100% use) 75.5 C
69.75 C 72.25 C

Idle temperatures averaged across all four CPU cores after a half-hour of inactivity. “Burn-in” temperatures measured after a half-hour of 100% CPU use on the Intel Burn Test utility.

Never Built a PC Before?

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