NVFlash: flashing the BIOS of NVIDIA GPUs

NVFlash is NVIDIA's console utility for reading and writing GPU BIOS. Miners use it to flash a modified BIOS: lower power draw, raise memory hashrate, or enable timings tuned for a specific algorithm.

⚠️ Flashing the BIOS voids the warranty and, if done wrong, can leave the card with a “black screen”. Proceed at your own risk and always keep a backup.

Preparation

1. Download NVFlash from the developer's official resource (TechPowerUp is a trusted source).
2. Extract the utility to C:\nvflash.
3. In Device Manager, disable every card except the one you are flashing (if you have several).
4. Launch the command prompt as administrator.

Backing up the current BIOS

Before any flash, always save the stock BIOS:

nvflash.exe --save backup.rom

Copy backup.rom to a USB stick or the cloud — this is your ticket to a rollback.

Flashing

nvflash.exe -6 modified.rom

The -6 flag bypasses the PCI Device ID check — needed when the image differs slightly from your revision. The utility will ask for confirmation twice — press y.

After flashing:

1. Shut the computer down completely (unplug from the wall for 30 seconds).
2. Power on and check the card in GPU-Z: the BIOS version should change.

If the card won't start

• Blind flash method: boot from a working card (or integrated graphics) and “blindly” run nvflash.exe -6 backup.rom once more.
• Full reset: nvflash.exe --index 0 -6 backup.rom, where the index is picked by trying 0–5.

Useful commands

Conclusion

NVFlash is a tool for confident users: three commands (backup, protect, flash) cover 95% of tasks. The miner's golden rule — no backup, no flashing.