WE KNOW WHAT you’re thinking: “This is odd.” And you’re right-it’s not something we’d usually cover here at Maximum PC. It’s not a gaming rig specced out to some arbitrary number set by the management bods, nor is it a deep-dive into the latest technological architecture from the likes of Nvidia (next issue-don’t worry!). No, this is something we’ve never done before: A case study and the chance to test something that very few people can get their hands on.
So, what are we talking about? Well, we’re heading back into the world of tubing and water blocks to take a look at one of the most radical types of coolant being developed and grown today: Mayhems’ 6nm XTR. Yep, you read that right-this coolant is synthetically grown in a lab. It’s unlike any coolant we’ve ever seen before.
However, there’s a few problems we need to overcome before we get to the testing phase. Firstly, as the Maximum PC office is currently shut, there’s only one machine we still have access to that’s capable of performing the tests we need: Our console-esque pink PC, which was designed for its aesthetics, with usability a secondary consideration. So, it doesn’t have a proper drain port nor a fill port, and we’ve got some serious conversion problems to solve.
But before all that, let’s dive into the history of liquid cooling, how it developed, and where it’s likely to go from here.
Kings of Cooling The problem with PCs
Noctua’s air towers are some of the most advanced phase-change designs around.
NO MATTER HOW you look at computing performance, it always boils down to electricity, tolerances, and heat. Those three factors have stymied unlimited power over the years. Diminishing returns are rife within this enthusiast hobby of ours. As transistor count goes up, gate width decreases, more voltage is applied, and heat increases, the need to cool components becomes more important to ensure they remain within their operating temperatures. To draw heat away from the processor and into something that can dissipate it into the open air has been of prime importance since the personal computer became a thing-in fact, even before that, with supercomputers.
Behold, the UNIVAC 1 in all its room-filling glory.
© GETTY IMAGES
The basic principle behind cooling any PC component is that you need a form of heat exchange to take heat from the system and dump it into the surrounding environment. Nowadays, you have a handful of options. Firstly, you could go with low-powered, efficient components (such as the Raspberry Pi), which can be passively cooled. Or you could run with an air tower that thrives off heat pipes, vapor chambers, and the brilliance of convection. You could also go with a basic form of liquid cooling in the form of an AIO (all-in-one) cooler from the likes of Corsair, NZXT, Cooler Master, et al. Or you could build your own complete custom liquid-cooled loop to chill everything within sight, albeit at far greater expense and risk if something goes wrong.
THE BASICS
Almost all of those options (bar passive cooling in ultra-low-powered chips) rely on a form of heat exchange or phase change to remove that excess heat. Take your standard CPU tower, air-cooled with a fan. By design, they typically have a solid, flat copper or nickel base, with heat pipes emanating out and up into a tower, which is then covered in an array of fins. This is then cooled by a fan, that’s either pushing or pulling a stream of cooler air over the fins, drawing that heat out.
This works through the power of convection. Each heat pipe or vapor chamber houses a small amount of liquid. When the processor is under load, it heats this liquid, which evaporates, forming a gas. Drawing the heat with it, it rises up through the heat pipe toward the fins. Here, cool air passes over the fins, drawing the heat out of the gas through the fins. The gas then condenses, changing back to a liquid, and flows down to the base of the heat pipe, ready to start the procedure all over again, very much in a loop. This is, in essence, a form of phase-change cooling, although not quite to the degree of some more extreme methods achieved by using a proper vapor condenser.
A liquid-cooled loop follows a near identical principle, just scaled up. Instead of heat pipes, you have tubing; rather than a copper base, you have a water block; instead of fins on a tower, you have a radiator; rather than vapor or condensed liquid, you have coolant; and instead of convection, you have a pump. This gives you a larger thermal capacity overall, and increases your ability to cool components with a larger thermal footprint.
In fact, it works in a very similar way as the cooling system in a car’s engine. A pump pushes coolant around (or antifreeze, in the case of a vehicle); it then enters a water block, where it heats up, then moves on through a radiator, which has cooler air passing over it, thanks to a fan or two, which draws the heat out of the coolant, ready for it to begin the cycle again. The advantage is that the coolant typically has a far higher thermal capacity than the liquid in CPU fan towers, and there’s a greater surface area for cooling the coolant, thanks to the radiator.