# Voltage glitching unlocks an A100 — a mining card gets 80 GB and full compute

> A voltage glitch on the GA100 die turns a cheap ex-mining card into a working A100-80G.

- Org: Kate (kate.land)
- Date: 2026-11-10
- Category: security, article
- Source: https://blog.kate.land/posts/using-voltage-glitching-to-unlock-the-a100/
- Canonical page: https://ai-tldr.dev/releases/kate-land-a100-voltage-glitch-unlock/

## In short

A researcher used a voltage fault on NVIDIA's GA100 chip to blow locked fuses and turn a CMP 170HX mining card into an A100-80G, unlocking about 80 GB of HBM and up to 126 SMs. NVIDIA was told before publication.

## What it is

The blog post 'Using voltage glitching to unlock the A100' describes a voltage fault injection flaw in NVIDIA's GA100 die that lets an operator blow fuses that should be locked. The author used it to re-enable features NVIDIA disabled on the CMP 170HX mining card, and published the tools in the ga100vfi repository.

## How it works

A precisely timed voltage glitch makes the chip accept fuse writes it should refuse, and because NVIDIA's design relaxes restrictions as more fuses are blown, extra fuses unlock hardware. On most cards tested, the full ~80 GB of HBM became usable, SMs rose from 70 to about 120–126, and PCIe Gen4 x16 turned on. NVLink needs a small board modification and a firmware check bypass.

## Why it matters

Cheap retired mining cards could become usable AI training and inference GPUs; the author measured 85.858 TFLOP/s FP16, above a retail A100's 72.488. The flaw also shows that fuse-based feature locks on data-center GPUs can be defeated with physical access. The author disclosed it to NVIDIA's product security team and notes another researcher found the same issue independently.

## Who it's for

GPU hardware hackers and AI infrastructure security teams

## Links

- [Blog Post](https://blog.kate.land/posts/using-voltage-glitching-to-unlock-the-a100/)
- [GA100VFI Repo](https://github.com/kate-land/ga100vfi)
- [HN Discussion](https://news.ycombinator.com/item?id=50451903)