DIY Mini SFF Watercooled Gaming PC (Steam Machine)

Hello everybody,

my latest project is an SFF computer with a volume of around 7.4 liters. The hardware components currently installed are not the best, and I plan to upgrade at least the GPU in the near future.

Specs:

• MSI B450I Gaming Plus AC

• Ryzen 7 3700X

• 16 GB DDR4 3200 MHz

• 250 GB M.2 SSD

• Zotac GTX 1060 3 GB

• HDPLEX 400W DC-ATX

The system uses an Alphacool NexXxoS 140mm XT45 radiator together with a customized Alphacool DC-LT 2600 water pump that runs at around 3000 rpm. The water blocks for the GPU and CPU are custom-designed and 3D printed with an Elegoo Mars 2 Pro. The cooling plates inside were salvaged from two Alphacool Eisblock water blocks.

For fittings, five 90-degree and seven straight connectors were used. To ensure better sealing on the 3D-printed parts, automotive silicone sealant was applied to prevent leakage, and an AquaComputer pressure equalization membrane was installed to prevent excessive pressure buildup.

Cooling is provided by a 120 mm Arctic P12 Pro for the radiator, one 40×20 mm Noctua fan for the PSU, and two 40×10 mm Noctua fans to supply airflow to the GPU’s VRAM and VRMs.

In terms of power and thermals, the system is more than capable of cooling the Ryzen 7 3700X with its PBO TDP of 88 W and the GPU’s 130 W TDP at a reasonable noise level, though further testing will be done. In the future, I plan to upgrade the GPU to something like an RTX 4060 Ti. Its TDP is a bit higher, but I believe the system can handle it. The only limitation is length, with a maximum of 180 mm.

For assembly, you will need M2.5, M3, and M4 threaded inserts and ideally a set of screws in different lengths for each size. You will also need an XT60E-F power connector and a selection of springs for the CPU and GPU water blocks. To connect the GPU, a 200 mm 90-degree PCIe riser cable is required.

Pictures and further tests and updates will follow soon.

EDIT:
The two FurMark screenshots show the CPU and GPU temperatures using two different fan and pump curves. One setup runs the pump and fans almost silently and results in higher temperatures, while the other runs them at full speed and therefore shows lower temperatures.

Build Video: