News · 2026-11-13

A voltage-glitching hack that blows GPU fuses turns an 8 GB mining card into an 80 GB A100-class card

A researcher writing as Kate published a voltage-glitching attack on Nvidia's GA100 chip that lets her blow arbitrary fuses, and used it to convert CMP 170HX cryptomining cards into effectively A100-80G cards. Her nvidia-smi output shows 81920 MiB on two cards. Tom's Hardware ran the headline "Techie uses voltage glitching hack to turn $2,500 Nvidia 8GB cryptomining GPU into a full-fat $20,000 A100 with 80GB of VRAM — hack carefully blows onboard fuses...".

Key facts

• Source: Kate's blog post, read in full.
• Speed claim: about 1.2 times a retail A100, because all functional SMs are enabled; she puts the count at roughly 120 to 126 depending on the die lottery, against 108 on production A100s.
• Method: voltage fault injection on the GA100 die, with new "fuseless fuse" rows written; it extends the earlier driver-level patch.
• Price caveat: the $2,500 figure is from a headline; price tables elsewhere show used cards at $1,300 to $2,000 or more.

Two different hacks

It is easy to blur this with the earlier unlock. The first is software. LTT Labs reported on September 12 that cmpunlocker, by Amogh Munikote, is a driver-level modification that makes the card show 64 GB (65,536 MiB) in nvidia-smi. The unlock is persistent per card, survives reboots, and must be rerun once per system and again after kernel updates. The card ships at 70 SMs against 108 on the A100 40GB; a 10GB variant has stability problems and reliably enables only about 40 GB. LTT notes PCIe Gen3 was announced as likely to come, but on-die ECC and Gen3 were not yet unlocked.

Kate's work is the second layer: a hardware attack. She found a voltage fault injection vulnerability on the GA100 die that lets her blow arbitrary fuses, and she writes new fuse rows to unlock capabilities the production fuses disabled. The approach needs a custom glitching board wired into the card, and each burn is tailored to the individual chip, so not every card unlocks fully. One search summary says nine of ten cards gave the full 80 GB, which was not verified.

What she says it unlocks

NVLink, PCIe Gen4, NVJPG, NVDEC and MIG are all unlockable this way, by her account, though she did not test NVJPG, NVDEC or MIG. Her method builds on Pry's June 2026 paper "A Canary in the Crypto Mine," which describes defeating stack protection in a GPU secure coprocessor. LTT added on September 15 that Petri Krohn published a video explaining the "FACEB13D" exploit. This is a real hardware-security story: fuses are how vendors segment products and enforce policy, and a glitch that rewrites them breaks a trust anchor.

Why local-inference folks care

The unlocked cards are being used to run large models cheaply. Repositories that pushed in the past week, including one running a W4A16 Qwen3.8-Flash-Next quant on two CMP 170HX cards with vLLM and another running an FP8 checkpoint on three or four cards, exist as of November 11, though their speed claims (226 tokens per second single-user in one description) are self-reported and unchecked. Artificial Analysis scores Qwen3.8-Flash-Next at 29 on its Intelligence Index above an open-weights median of 24. Our lesson on quantization explains the W4A16 notation.

The A100 price story is unconfirmed

A Reddit thread claimed A100 prices were falling 20 to 30%. The GPUDojo tracker, which shows only the lowest eBay listing at weekly snapshots, shows the A100 40GB at $5,850 on November 13, near a 90-day high, up from $3,500 on October 2. The 80GB is at $10,999, down about 12% from $12,500, flagged at a 90-day low. The claim was not supported. No source tied the hack to Nvidia leadership either.

Caveats

The Tom's Hardware page loaded only partially, so the body was not read; the primary source is Kate's post. Speeds and card counts are the researcher's. Fault injection is destructive: it blows fuses, and a mistake can brick a card.

Primary source, verified: read the paper →

Ground Truth. (2026, November 13). A voltage-glitching hack that blows GPU fuses turns an 8 GB mining card into an 80 GB A100-class card. Ground Truth. https://groundtruth.day/news/voltage-glitching-hack-turns-an-8gb-cmp-170hx-mining-card-into-an-a100-80gb.html

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  title  = {A voltage-glitching hack that blows GPU fuses turns an 8 GB mining card into an 80 GB A100-class card},
  author = {{Ground Truth}},
  year   = {2026},
  month  = {nov},
  url    = {https://groundtruth.day/news/voltage-glitching-hack-turns-an-8gb-cmp-170hx-mining-card-into-an-a100-80gb.html}
}

Topics: cybersecurity · hardware-security · fault-injection · nvidia · a100 · cmp-170hx · local-inference