Premium Build: Greyscale — building a custom-looped ITX PC that pushes the form factor to its limits

To cool “Grayscale,” we’d turned to Alphacool. We’ve never done a build with Alphacool watercooling gear, so were eager to try their range out.

Because we’re cramming a 9950X3D and an RTX 5090 into a system the size of a shoebox, we would be needing full-copper radiators, as these are highly effective at dissipating heat. For this purpose, Alphacool’s HPE series perfectly fit the bill.

The plan was quite straightforward. At the bottom of the NCase M3 would be a regular 30mm 280mm radiator with two of Phanteks’ new 14omm T30 fans (the company finally released them last month, five years after the 120mm version.) These fans are 30mm thick, which is 5mm more than the industry standard, and built with LCP, they are true high-performance kings.

At the rear exhaust, there would be a 120mm pump/res combo unit. This unit would be installed on its standoffs to ensure air could still escape through the vent it’s mounted on by means of positive pressure in the case. So, although there would be no fan there, I did plan on a 120mm intake fan on the side of the case, between the PSU and the motherboard.

At the top of the case, the motherboard would stop us from being able to install a 280mm radiator, so it would have to be 240mm; however, we did have vertical space, so this would be a 45mm thick radiator, again with Phanteks T30 fans installed, for a total combined thickness of 75mm. With better breathing space, this radiator would be doing most of the heavy lifting.

Lastly, the system will use soft matt-black tubing, in a thick 16/10mm (OD/ID), for nice chunky-looking tubes. Although they would be inflexible due to this thickness, which is particularly challenging in a small case such as this, they have a chunky, utilitarian look. Hopefully, this is not a choice I’d regret later.

Installing the CPU Block

To install the CPU block, we first prepare the CPU by cleaning the old paste off it, and swap the factory bracket for the mounting screws included with the block kit. Then, we give it three dots of thermal paste, and chuck the Alphacool Core 1 Aurora Silver into place.

Although it’s ‘just’ a CPU block, these copper blocks are quite weighty.

Radiator & fan install

After the CPU block, I installed the two radiators. The slim 280mm unit at the bottom of the case, and the 45mm 240mm radiator at the top. Although there’s an option for taller feet from NCase, I don’t find that lifting the chassis up any further looks particularly charming, but it also means the lower radiator wouldn’t be able to get a lot of air. This meant the top rad would be doing most of the heavy lifting.

Then, I dropped the Phanteks T30 fans into place. One immediate issue was that the CPU block’s intake port was blocked by the corner of one of the fans. This was going to be a problem later on, but we’ll get to that in a bit.

Reservoir & Pump Install

The Alphacool Core 120 pump-res combo unit is a beautiful bit of kit that slots right onto a 120mm fan mount. I debated for a few moments whether using this reservoir would be a wise choice – it did mean sacrificing the rear exhaust fan slot, but I really did not want to turn to a tubular reservoir in the middle cavity of the build – I didn’t find that it would look cohesive, and in all truth, I find that cylindrical reservoirs look a bit dated.

Unfortunately, mounting the reservoir wasn’t as straightforward as I had hoped. The NCase M3 is built from beautiful, thick, anodized aluminum, and the screws to mount the push-pin system with spacers weren’t long enough.

With the gear I had, I could have opted to mount the reservoir flush against the case, but this presented three issues:

• The side drain port would be unusable
• The chipset fan on the motherboard would get zero airflow
• It would leave the rear exhaust fully obstructed, so even positive pressure wouldn’t work so well here.

Thankfully, the vast majority of screws used in PC builds are standard M3 threading, so I ran over to my local hardware store and grabbed four M3x10 screws.

With these, I was able to mount the reservoir in place, and all was good in the world again.

A 3D game of Tetris

Now that the radiators, fans, power supply, and pump-res unit were installed, it was time to evaluate the viability of the layout.

The first revision made was flipping the top radiator to feature the ports on the rear instead of the front of the case, as in the previous configuration with the ports at the front, the fans would make the inlet port of the CPU block inaccessible.

Making this change did mean that I would be cramming a ton of fittings into a very small space, but there was no other way of making it work. I also pulled the radiator as far forward as possible. This gave me just enough clearance for both ports on the CPU block.

I also contemplated adding a third radiator. I have a few extra 120mm radiators that I use for fan testing, so I test-fit one of them, to see if it’d work.

Unfortunately, it would mean the top radiator wouldn’t fit in the intended spot anymore, and I was about 10mm short on clearance. If I were to use a 25mm thick fan, and a 25mm thick radiator, it could save 5mm on each and it would work, but I didn’t have a 25mm 120mm radiator at my disposal, so it sadly wasn’t going to happen.

I also experimented with every possible alternative for positioning the power supply. In the position I had it originally, the motherboard and GPU cable were long enough to tuck away tidily, but the 8-pin cable EPS cable to power the CPU wasn’t long enough to route out of sight. But, there was no better layout, so the CPU's power cable was going to remain visible. I should have measured this all out before and placed a CableMod order, but alas.

I placed the GPU block without the graphics card in, and pictured above is the final layout I decided to go for, but there was one crucial factor looming. As much as I wanted to use them, it did not look like I was going to have space for the Phanteks T30-140 fans on the bottom radiator.

But before going out and finding regular 25mm thick fans, I decided I had to install the GPU. Who knows, we may get some extra clearance with it installed.