Voltage Glitch Turns $500 Mining Card Into A100-80G
Original: Using voltage glitching to unleash the A100 in my mining card
Why This Matters
Demonstrates that NVIDIA's hardware feature locks are bypassable with physical access, raising supply-chain and data-center security questions.
A researcher used voltage fault injection on NVIDIA's GA100 die to blow arbitrary fuses, converting a CMP 170HX 8GB mining card into a functional A100-80G with 81920 MB VRAM and 1.18x faster FP16 performance than retail.
Security researcher Kate has published a detailed account of converting NVIDIA's CMP 170HX — a cut-down, crypto-mining-only GPU — into what functions as an A100-80G, using a hardware attack technique called voltage fault injection. The CMP 170HX shares the same GA100 silicon as the A100 but has features disabled via what NVIDIA calls 'fuseless fuses,' essentially software-controlled registers that mimic burned fuses. Kate found three exploitable fault injection states: one where all fuses read as zero, one where the RIR (register read) is disrupted, and a 'Goldilocks' glitch that allows writing arbitrary fuse values. By triggering the vulnerability at the right moment, she could unlock the full 80GB framebuffer, all compute SMs, PCIe Gen4, and NVLink (12 lanes). The retail A100 ships with 108 SMs enabled as a yield-safe default; Kate's unlocked cards ran 120–126 SMs depending on the die, hitting 85.858 TFLOP/s FP16 versus the retail A100's 72.488 TFLOP/s — a 1.18x uplift. Memory bandwidth also checked out at over 1,880 GB/s. Features like MIG, NVJPG, and NVDEC are theoretically unlockable by the same method but were not tested. The two unlocked cards also communicate via NVLink at 12 lanes, as confirmed by nvidia-smi topology output.