Sidenote: Making the Decision to Build A Custom Watercooling Loop For My Next System

It is the sharp escalation of tension in a build I am seeking, I guess.

For most of my adult life, I’ve been a tech enthusiast and have built about a dozen systems for myself and friends/family. Rookie numbers by some measures, surely, but a pretty broad roster of different setups, hardware types, and such over those years.

However, these is a cooling frontier I have never crossed in proper fashion until my upcoming build – custom-loop watercooling.

I’ve used a few closed loop liquid coolers before. My current system has two, in fact, one for the CPU and a hybrid cooler including one for the graphics card. My dual-CPU EVGA Classified SR-2 system had two of the very first generation Corsair hydro series closed-loop systems on the CPUs, until one of them sprung a leak and murdered my Geforce GTX 680 graphics card after confusing me with random thermal throttle shutdowns.

On the surface of it, watercooling is a fucking scary idea. Computers hate water, it turns out! If water touches a computer with power even so much as stored in a capacitor, you’re likely to have a very bad time (as my dead Geforce GTX 680 can attest). Closed loop coolers tend to carry the assurance of some sort of warranty that usually includes a degree of leak coverage – manufacturers still know that the idea of a liquid cooler is scary and the pricing on today’s higher-end closed loop systems is quite high given that they often only cool one component, so you need a way to reasonably break people into the market.

For me, open loop was a sort of final frontier. I don’t have the patience for extreme overclocking, so I’ll likely never actually try chilled radiator watercooling, liquid nitrogen, or any of those sort of temporary benchmark run cooling systems, but I have wanted to try building my own custom loop for a long time. When I had a basically unlimited budget with my SR-2 system, I got very close to doing it. I bought a Mountain Mods case that could support a lot of radiator capacity, I found waterblocks that would work for my CPUs and GPUs, but I chickened out and bought the Corsair CPU coolers and ended up getting aftermarket heatsinks for my Radeon HD 6970s. They worked fine (well, except one of the Corsair units going rogue and nuking the previously-mentioned graphics card), but it was always a compromise I made and hated – getting triple graphics cards for Crossfire X (which was almost completely non-functional, unless buildings in Stormwind disappearing and reappearing counts as “functional”) pulled budget away from what I would have spent on watercooling parts.

It also was, well, really scary. Watercooling in 2011 was still sort of a niche within a niche – it was becoming vastly more popular as hardware ratched up thermal dissipation requirements, but the options for parts were still slim. Radiators made for watercooling came in a few common sizes, waterblocks were usually one-size-fits-all affairs, and then there were all the questions after that – GPU cooling, pump and reservoir options, fluid additives for anti-microbial and anti-corrosion purposes, managing tubing and fittings, how scary to an outsider the concept of a barbed fitting held on with a firm press-fit and sometimes a clamp or even a zip tie was, and the question of what kind of performance you were gaining at that cost. There also just wasn’t a huge amount of information like video tutorials or guides that made the process easy enough to risk for someone nervous about nuking their hardware.

For the uninitiated, watercooling serves the same fundamental purpose as heatsinks and fans in a computer, but accomplishes the cooling of hardware in a somewhat different manner. Most modern heatsinks use a copper base plate that touches the hardware needing cooling, and then uses either heatpipes or a vapor chamber to move the heat to a stack of fins, usually made out of aluminum, which are stacked to increase surface area and allow a fan to blow air through them. The fins radiate heat into the air, which the fan’s airflow picks up and moves out towards an exhaust in your computer case. The CPU socket is usually right next to the primary exhaust in most systems, and that is often also fitted with a fan to direct airflow. In a graphics card, the fan is usually at the front of a shroud around the card, pulling air in, blowing it through the shroud and over the heatsink further inside, with the air then exiting out the back of the card where you plug in your monitors.

Air cooling is fairly effective at most price points because parts like CPUs maintain low-ish thermal requirements even today, relative to how graphics cards have exploded in thermal dissipation required for smooth operation. A simple heatsink with enough fins to increase surface area and a simple fan can do the required work well enough at a low cost, with only the fan being a notable point of potential failure. It also doesn’t heat-soak very much, as most of the heat directed into a heatsink will either be blown away by a fan or will naturally radiate out of the heatsink, although this process can cause increases in ambient case temperature in a poorly-ventilated PC case. But generally, if you have a reasonably designed case with at least a fan to direct airflow over components and out of the case, you’re good. Even a single case fan as exhaust can do wonders, as the negative air pressure this creates will pull air in through openings in the case and bring down case temperature as the air moves to the exhaust fan.

However, air cooling has practical limits for what it is capable of. Modern CPUs (especially the top end Core i9 lineup from Intel) can run very hot due to performance features. Pretty much all modern CPUs and GPUs employ various boost technologies, meant to increase performance during opportune moments. For CPUs, they’ll self-increase their clock speeds based on current loading of cores, and AMD’s Ryzen uses a bevy of sensors on-board the silicon to manage clocks based on power usage, workload, and temperature. For GPUs, they’ll boost up and down depending on how loaded the GPU is, what temperature it is running at, and up to a given value of voltage and board power consumption. Air-cooling can effectively allow for boosting to happen, but there is a finite amount of weight that can be mounted on most CPU sockets and graphics cards to avoid physical hardware failures.

An overweight CPU cooler can bow a motherboard if mounted improperly, and older systems could even have motherboards snap if the heatsink was too heavy. Both AMD and Intel publish a maximum specification for the amount of weight the socket heatsink clips can bear, but manufacturers will work around this by using custom mounting clips that replace or supplement the stock ones, usually by bracing the socket area from the back with a custom backplate. GPUs likewise have weight limitations that, if exceeded, can cause the GPU to sag or even tear out of the PCI-Express connector. Most graphics card designs sold by board partners of Nvidia or AMD are 2.x slot designs, designed so that the card occupies the space of 3 expansion cards, giving it an additional IO bracket slot to screw down to aid in weight carriage. Most modern graphics cards also use metal backplates and reinforcing brackets on the frontside of the PCB to brace the card to the IO bracket, reducing sag by increasing the rigidity of the card and pulling some of the weight towards the braced IO shield at the rear of the case. A lot more designs lately have given up the 2.x slot designs for flat out 3 slot designs, adding another layer of IO bracket that can be screwed down to the case to aid in keeping the card stable in the slot, and motherboard manufacturers are also starting to help by offering their main PCI-E slots with metal reinforcement to keep the slot itself stronger. Lastly, some board manufacturers will just throw in a retention brace with cards, which you screw in below the card and serves like a shelf arm to just hold the heatsink up from underneath!

Watercooling aims to fix this in a few ways.

Firstly, it is more efficient as water has a higher heat capacity than air. To leverage this, a watercooling system needs a couple of components: a pump to move water through the system, a radiator or heat exchanger to remove heat from the water, a reservoir to hold water capacity and aid in bleeding the system (while not strictly required, building a watercooling system without a reservoir is substantially harder), waterblocks to make contact with the components to be cooled and allow them to transfer their heat into the water, and coolant of some sort (most usually, well…water, but there are specialty coolants, show coolants, and most closed loop coolers use a mix of water and propylene glycol to prevent freezing fluid when in shipping). Slap some fans onto the radiator and you’re all set to go, as the coolant pumps through the system, running onto coldplates in the waterblocks (usually over microfins designed to work like a tiny heatsink and increase heat transfer), carrying the now-heated water to the radiator which absorbs the heat out of the coolant and has fans to whisk it away.

Waterblocks are often lighter than full-blown air coolers for similar or higher performance than the best air coolers, taking advantage of the increased heat capacity of water. Radiators mean the heat exchange to air happens further from the heat generating components, creating some improved efficiency, and the larger surface area of a radiator setup compared to heatsinks means fans can move slower and quieter while still matching or exceeding the performance of a top-of-the-line air cooler.

So with the process explained, why am I moving to it with my next build? Well, I have a few goals it helps me to meet:

Maximizing Boost Clock Performance and Slight Overclocking: Cooling is crucial to ensuring steady boost clocks on graphics cards and AMD CPUs, as the lower the load temperature is, the longer it can maintain boost clocks and the faster the resulting boost clocks can be. Nvidia cards boost up in “bins” of 15 MHz, and can do so right up to the power limit of the board. My current 1080 Ti has a spec boost clock of 1670 MHz, but often boosts right up to below 2 GHz and maintains around 1930 MHz in most heavy games like FFXIV. AMD’s CPU boost works somewhat similarly, with a maximum speed that is pretty strict and usually only obtainable on 1-2 cores. For the 5900X, that is 4.8 GHz. It can adjust up and down in 25 MHz increments based on evaluation of current usage, power usage, and temperature, and will often make microadjustments for fractions of a second to burn through a task before clocking back down.

For both components, overclocking is typically best done (and in the GPU’s case, only possible via) adding an offset to clock speed. So you can add a +200 MHz offset, making the CPU capable of boosting up to 5 GHz on 1-2 cores, or adding 200 MHz to the GPUs base clock, increasing all resulting clocks including boosts (provided that this does not exceed the power limit of the card, which is strictly enforced short of a BIOS flash or a shunt mod to remove power limits). For the CPU, I can turn on a feature called Precision Boost Overdrive and AutoOC, removing the stock power and temperature limits to increase them to a higher level, and to then use AutoOC to apply the clock speed offset. A strong watercooling loop and a strong power supply means I can supply enough power to increase speeds and cool the extra heat that generates sufficiently. Likewise, getting a quality RTX 3080 will ensure higher power limit and better power delivery hardware, and the same applies to the voltage regulation hardware for the CPU on a good motherboard. If I cover these factors, then cooling remains the weak link, and watercooling with a high heat capacity via radiators and smart fan control means more performance!

Quieter Operation: My current system isn’t awfully loud, but to ensure better performance, I use high fan speeds. This is fine, but it is compounded by a couple of issues. The first is that by using closed loop liquid coolers on both the CPU and GPU, I have two pumps making noise – pumps being notably whiny and higher-pitched devices. The second issue is that one of these has some sort of air retention issue, which impacts cooling slightly, but primarily annoys by being louder, as the air pockets make a gurgling noise when entering and leaving the pump, which I have not been able to resolve. It hasn’t been enough to cause pump failure, and I expect that tearing the system down and rebuilding it when giving it to my wife should resolve the issue, but it remains annoying for now and the amount of time it would take me to fix it for myself is not something I’d like to spend. Lastly, the hybrid cooler on the GPU has a louder fan on the VRM hardware for the graphics card, which creates an excess amount of noise. I can run it slower or let it auto-adjust, but the pitch of fans auto-adjusting speeds bothers me more than a higher fixed speed, so I tend to run fans between 80-100% and let them stay there (it makes fan selection at purchase more important, but isn’t as bad as it sounds) but for that VRM fan, it is consistently too loud! Going to a full custom loop means fewer fans, all fans under firm control by me, and with the drastic increase in cooling capacity with full contact GPU waterblock, CPU waterblock, and more than double the total radiator mass compared to my current closed-loop dual coolers, I should be able to spread the heat to more radiator capacity, soak more heat from the graphics card, and then be able to run the smaller number of fans at a slower speed.

For the Challenge of It: Watercooling is something I’ve wanted to do and the performance concerns of the new hardware meant I could reasonably justify it. Going with hard tubing (using PETG, a plastic tubing, which must be heated and bent to shape to fit your runs inside the case) is a bigger challenge still, but one that will pay off in a way we’ll discuss later. My hope is that by having time to work on the system piecemeal as parts come in (base components in late October, CPU in early November, GPU with preinstalled waterblock in mid to late November), I’ll be able to overcome my natural impatience and spend quality time really building things out to a high standard, since without all the parts, I won’t be in a mad rush to finish the system so I can fire up games at higher settings and framerates.

Cost to Performance is Actually Decent: Going with mid-market brands for waterblocks instead of rushing right to EKWB means getting parts for less. Buying an EVGA Geforce RTX 3080 Hydro Copper with the waterblock for that preinstalled means not paying for (or having to store) a loose heatsink and reduces the cost of the whole bundle. When I first set out to price hardware with custom loop cooling, a CPU cooler I wanted was $300ish, and getting a Hybrid card for graphics from EVGA or a highly efficient air cooled card would cost about the same as the Hydro Copper version. The added cost of radiators, a pump, a reservoir, and tubing/fittings, while not inconsequential, isn’t as big as I feared, and given the performance improvements, I think it will be a worthwhile investment.

It Looks Really Cool: Hardline clear tubes filled with water, flowing through your system, with RGB LEDs illuminating it and being amplified by the water and the rounded clear surfaces full of it, the fittings adding little catches of colored metal, the large tube reservoir towering over the hardware – open loop watercooled systems just look really, really cool. For something I want to hold onto for at least 3 years, this should give me exactly what I want without getting the desire to change out cooling.

It Makes Upgrades Harder: Going with a custom loop and hardline tubing means a simple fact – any attempt to swap hardware requires draining the loop, undoing all the tubing and removing parts, swapping out a part for upgrade, and then re-plumbing the whole thing, re-bleeding the loop, testing for leaks, and only after all of that can I resume using the machine. Yikes. It still allows for storage upgrades easily enough since the drives are all in the rear of the case, but if I dare to think about a new CPU, GPU, or RAM kit, it gets drastically harder, chaining down my constant desire for newer and better!

In the end, my hopes are that this will give me the performance edge I am looking for, while having a prettier, quieter system even more worthy of being a showpiece!

One thought on “Sidenote: Making the Decision to Build A Custom Watercooling Loop For My Next System

  1. My main issue with cases has always been dust. We have a lot of cats, with a lot of litterboxes, and as a result a lot of clay-based litter dust, which is just the worst. I tend to mitigate this with filters and the judicious use of positive case pressurization. I did once stray into the weeds with a Lanboy Air (, which looks mega cool, but is the absolute worst at keeping dust out.

    Temperature, other than the way it is contributed to by dust (insulation). has never been an issue, and I usually employ more conventional ways of improving the cooling rather than lay a tank of water somehwere in the chassis.

    Water cooling DOES look pretty cool, especially if you use black lighting and UV dyes in the liquid. But my vanity doesn’t get me past the idea of IT’S WATER 🙂

    In my experience, the excessive temps tend to go away by the 2nd or 3rd cost-reduction pass, but that, of course, means that whatever it is is no longer bleeding edge. That’s okay. I’ll let the people with money to burn have the fun, I’ll come along later and reap the rewards 🙂

    EXTREME cooling idea: water cooling but with MERCURY. I know it’s been used for cooling, just sketchy on the details as to where.

    Liked by 2 people

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