Hobbyist uses voltage glitching to unlock Nvidia CMP-170HX mining cards into A100-class GPUs
The flaw cannot be patched on cards already sold, so the effect on the used market will depend on how widely the technique spreads.
A hobbyist known as Kate used a voltage glitching technique to bypass protections on the eFuse controller of an Nvidia CMP-170HX mining card, letting her re-enable disabled memory and compute units. Nine of her modified cards reached the full 80 GB of VRAM, while one was limited to 64 GB, and unlocking all shader modules gave her about 20% higher FP16 FMA throughput than a standard A100. Her best test card ran at PCIe 4.0 with the full feature set, which the earlier soft mod did not allow. The cards cost roughly $2,500 to $3,000 against $20,000 or more for a PCIe A100 80GB, though prices may shift as the mod spreads. Kate reported the flaw to Nvidia, but the company has little it can do for cards already sold.
Why it matters
The modification shows that protections on the eFuse controller of these mining cards could be bypassed by a hobbyist with hardware access, which makes the cards far more capable than their original sale price suggested. Buyers of used CMP-170HX cards now get near-A100 memory and performance for a fraction of the cost of a PCIe A100 80GB. Nvidia has informed of the flaw but has little ability to fix cards already in circulation, so the gap between mining-card prices and data-centre GPU prices is likely to narrow as the method is shared.
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