Nvidia crypto mining GPUs hacked to restore locked-away VRAM — software mod unlocks 64GB of VRAM on $250 CMP 170HX

Now that the best graphics cards are worth a fortune for both gamers and AI enthusiasts, modders have resorted to hacking Nvidia’s older Cryptocurrency Mining Processor (CMP) series, originally released five years ago, as a way to overcome the ongoing memory shortage and ludicrous prices. CMP Unlocker, a completely software-based solution, has restored the previously locked-away memory on the CMP 170HX, boosting its memory capacity by up to 8X — from just 8GB to a massive 64GB, and from 10GB to 40GB.

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To truly understand how the hack works, you need to dissect the CMP 170HX. The CMP 170HX is the flagship SKU in Nvidia's CMP series and leverages the GA100 (Ampere) silicon. It is the same 7nm die that powers the more expensive A100 accelerator. Unlike other Nvidia silicon with separate soldered memory chips, the GA100 itself is a monolithic chip with on-package memory. That means the total amount of memory is physically present on all GA100 silicon, so it comes down to how many memory stacks are active.

The GA100 silicon features a total of six HBM2e memory stacks. Depending on the SKU Nvidia is aiming for, it could have five or six memory stacks enabled. The chipmaker carves the CMP 170HX from defective or binned GA100 silicon that did not meet the stringent quality requirements for the enterprise-grade A100. Nvidia officially sold the CMP 170HX in 8GB and 10GB variants. All the chipmaker did was disable the additional memory through firmware, along with other limitations, such as nerfing compute performance and PCIe interface speeds.