Billet Labs modders created a unique gaming PC inside a cast-iron radiator, weighing 99 kg with a custom liquid cooling system. Features Ryzen 7 9800X3D and RTX 5080.
© Billet Labs
Modders from Billet Labs have unveiled one of the most unusual gaming PCs in recent memory—a system built inside an actual cast-iron heating radiator. The final version of the project is now complete, and the creators have shared photos of the device, noting its impressive total weight of 99 kilograms. In this build, the radiator isn't just for show; it serves as a full-fledged heat exchanger for a custom liquid cooling system.
Inside this unconventional case lies modern hardware: a Ryzen 7 9800X3D processor, a GeForce RTX 5080 graphics card, and 32 GB of RAM. The entire system is cooled by a liquid loop with a capacity of about 18 liters, which is significantly larger than typical PC liquid cooling setups. According to the project's author, the build took roughly three months of work, mostly in full-day sessions. Excluding filming and documentation, the assembly itself could have been completed in about a month.
Durability received special attention: a corrosion inhibitor was added to the loop after users expressed concerns about using cast iron in a system with coolant. Temperature tests were conducted until thermal equilibrium was reached, which Billet Labs reports took between 60 and 90 minutes. Even with the fans completely turned off, the coolant stabilized at 26°C in Spider-Man 2 and 29°C in Cyberpunk 2077, with ambient temperatures of 16–17°C.
Average component temperatures also remained quite moderate: in Spider-Man 2, the CPU heated up to 60°C and the GPU to 65°C, while in Cyberpunk 2077, the figures were 68°C and 69°C, respectively. Total system power consumption reached 352 W in the first case and 398 W in the second, with the load distributed between the CPU and GPU.
Additionally, a combined stress test was performed using Cinebench and FurMark with fans at 10% speed and the pump at 100%. Under these conditions, the coolant temperature was 29.25°C, and the difference between the water temperature and ambient air was 13.25°C. As the system heated up, overall power consumption dropped from 520 W to 447 W, which the developers attributed to a reduction in GPU overclocking and a slight drop in CPU performance.
From an engineering perspective, the project is impressive, but its practicality remains questionable. Not every desk can support a gaming PC weighing nearly 100 kg, and the computer will heat a room just as effectively as a standard heating radiator. However, in colder months, this "PC-heater" might not be a drawback but an unexpected bonus.