A community-developed driver-level hack now unlocks all 40 compute units on ASRock’s BC-250 mining board, transforming a sub-$150 repurposed GPU into a Steam Machine with more cores than a base PlayStation 5.
Technical background
The BC-250, originally designed for cryptocurrency mining, uses binned AMD SoCs derived from the PS5’s custom chip. Out of the box, only 24 of the 40 compute units (CUs) are enabled, as the remaining cores may contain manufacturing defects. The board includes 16GB of GDDR6 memory and is typically run with Linux gaming distributions like Bazzite.
The unlock, documented by GitHub user duggasco and highlighted by YouTuber ETA Prime, works via a kernel module parameter. During GPU driver initialization, the patch writes to two hardware registers, activating all 40 CUs. The modification also raises power draw to 125W at 1,500 MHz; the developer recommends a 900 mV undervolt to manage thermals. Overclocking to 2 GHz, a common enthusiast target, can overwhelm the board’s cooling system.
Performance gains and caveats
Benchmarks show significant improvements across modern titles at 1080p high settings with a 2 GHz overclock. In Cyberpunk 2077, frame rates rose 17% (from 36 to 42 FPS). Hitman 3 improved 19% (58 to 69 FPS), GTA 5 gained 24% (58 to 72 FPS), and Spider-Man 2 saw a 28% uplift (36 to 46 FPS). ETA Prime recorded up to a 28% overall performance increase with the full 40 CU configuration.
The hack carries inherent risk. Because the BC-250 uses binned dies, enabling all 40 CUs does not repair defective cores. Users must rely on silicon lottery outcomes; the patch also supports partial unlocks of 32 or 38 CUs for chips with some failed units.
Strategic implications
This development underscores the growing viability of repurposed enterprise and mining hardware for consumer gaming. The BC-250’s integrated GDDR6 memory eliminates the need for separate RAM, further reducing build costs. As component prices remain volatile, such hacks offer a low-cost entry point for DIY gaming systems without sacrificing modern game compatibility.
Forward outlook
The BC-250 unlock represents a broader trend: community-driven firmware modifications are extending the useful life of specialized hardware. While binning and thermal constraints limit reliability, the performance gains demonstrate that even binned silicon can compete with mainstream consoles when fully enabled. For budget-conscious builders, this hack turns a mining castoff into a credible Steam Machine—provided they are willing to accept the silicon lottery’s verdict.
