Nvidia's Secret 64GB Chip Unlocked
Nvidia's CMP 170HX was originally designed for cryptocurrency mining in 2018 and came out with 8 GB of memory. However, it appears that the card had 64 GB of physical HBM2e memory all along, locked by firmware.
The unlock exploits a signature-loading bug in the BootROM of the Falcon security microcontroller, which allows users to access the full 64 GB of memory using the open-source nvidia-open driver. The patch survives a reboot and provides significant performance gains, but there are still some caveats: ECC support is unresolved, NVLink and PCIe Gen4 are not working, and the 80 GB threshold was tested but rejected as unstable.
The price of the CMP 170HX has skyrocketed from around $250 to over $1,000 on eBay since the exploit became public. ValdikSS notes that he hasn't found any evidence of genuinely faulty RAM, suggesting that the throttling may be a form of commercial segmentation rather than recycling failed chips.