Count the radiators in this pink water-cooled gaming PC build

If you think the 240mm AIO cooler strapped to your CPU is pretty good, then prepare for your rig to be humbled into the corner by the monstrous cooling power here. This open-air water-cooled PC has four (yes, four!) 360mm radiators, meaning it can happily cool its high-end components while making barely a whisper of noise, and the water-cooling loop stands out from a mile off with its pink/magenta coolant.

Custom PC has been celebrating the best PC builds since 2003, and our Facebook group has over 390,000 members. We’ve seen many custom gaming PCs, from case mods to scratch builds. Here we chat to Oliver about how he built this glorious open-air PC build.

Where do you start when building a system such as this one? For Oliver, the main starting point was the fabulous open-air Yuel Beast Atlas II chassis, which is made by boutique PC case maker Eric Mihal in small batches.

Eric’s cases aren’t cheap – the Atlas II starts at $345 – but they’re supremely flexible, and enable you to assemble a PC that really makes a statement. ‘The Yuel Beast Atlas II case has the advantage that only a few components need to be in a certain place,’ Oliver explains, ‘and many components can be arranged in different ways.’

Oliver already had a rough idea of how the cooling system would work before he started. ‘The idea at the beginning was to have six fans symmetrically placed at the top and bottom,’ he says. ‘Then I simply arranged the components and tubes as symmetrically as possible, and in straight lines.’

Believe it or not, that magenta coolant is circulating around a single water-cooling loop, rather than four separate ones for each radiator, made with EK Quantum water-cooling components, along with an Alphacool flow meter. Unlike some water-cooling aficionados, Oliver largely built the water-cooling system using measurements and his eyesight, rather than spending hours drawing up the system in CAD.

‘I first placed the components to my liking and then measured the distances,’ he says. ‘For the sake of simplicity, I made sure that the tubes only had to be bent on one level and that they were always bent at 90-degree angles. I used some tools from Alphacool to bend them. To be honest, a lot of it was a matter of measuring by eye, especially when shortening the tubes.’

Did it matter which components went where in the loop? ‘A specific order of the components in the loop was not crucial for me,’ he says, although he adds that ‘I wanted to mount the GPU with the coolant visible to the front – it’s an active backplate though, I could have turned it around.’

What was the most difficult part? ‘The very straight tube between the two radiators,’ Oliver tells us. ‘Acrylic glass is very rigid when cold and susceptible to fractures. It only worked when I screwed in one of the fittings to the radiator after inserting the tube.’

With the cooling capacity of four 360mm radiators fitted with 12 be quiet! Silent Wings 4 fans, Oliver has no trouble cooling the top-end components in this rig. The spec includes a 24-core Intel Core i9-13900K CPU, and an Nvidia GeForce RTX 4090 GPU, but Oliver is more interested in using this cooling power to keep his system quiet, rather than to overclock his components.

‘I really like open cases,’ he tells us, ‘but at the same time, I’m quite susceptible to noise. The system is completely inaudible with the fans below 800rpm in a rather quiet environment, even with a completely open case.’

In fact, Oliver tells he usually only runs the fans 12 fans at 10-20 percent of their rated speed, meaning they’re often running at just 600-800rpm. He says they rarely run above 30 percent of their rated 3,000rpm speed.

What sort of temperatures do you get with this sort of cooling power on tap? ‘The last time I paid attention to temperatures, MSI Afterburner recorded a maximum GPU temperature of 52°C in Cyberpunk 2077 with ray tracing maxed out after about an hour, but it averaged below 50°C.’ As a point of comparison, the RTX 4090 Founders Edition hit  67.5°C in our testing. ‘The average CPU temperature was in the same region,’ says Oliver, but adds that ‘it spiked in the low 80s.’

Finally, we have to ask about the color of the coolant. We’re not sure if we’d call it pink or magenta, but it certainly makes a statement. ‘Honestly, my kid chose the color!’ says Oliver. ‘However, it went great with the white, black, and silver color scheme, and I wanted a futuristic-industrial look.’

Would Oliver do anything differently with the benefit of hindsight? ‘I’m actually more than happy and would probably not do anything fundamentally different!’ he says. ‘In retrospect, I probably should have made the tube between the flow meter and the GPU a little shorter (you can’t see that in the pictures, but I know that half a millimeter less would have been “more”). Also, I probably would have made the connection between the radiator and the CPU out of a single tube, not two, as in the current build.’

Magenta water-cooled PC specs

• CPU: Intel Core i9-13900K
• Motherboard: Asus ROG Maximus Z790 Apex
• Memory: 32GB Corsair Dominator Platinum 5600MHz
• Graphics card: Asus ROG Strix GeForce RTX 4090 OC
• Storage: 2 x 1TB Kingston KC3000
• PSU: 1,200W be quiet! Dark Power Pro 12
• Case: Yuel Beast Atlas II
• Cooling: 4 x EK-Quantium Surface S360 radiators, EK-Quantum Kinetix FLT 240 D5 PWM D-RGB Plexi pump/res combo, EK-Quantum Vector² Strix RTX 4090 D-RGB Nickel+Plexi GPU waterblock, EK-Quantum Magnitude LGA1700 Full Nickel CPU waterblock, Aquacomputer Flow Sensor, 12 x be quiet! Silent Wings Pro 4 PWM fans