NVIDIA CMP 170HX GPU Unlock for up to 80 GB of VRAM with CMPUnlocker

CMP 170HX Unlock Tools

The CMP 170HX, which was released in 2021 at the height of the mining boom, is a stripped-down version of the Ampere A100 architecture. Originally, the cards shipped with either 8 GB or 10 GB of VRAM and offered no support for 3D rendering; after the crypto market crash, they were largely sidelined.

The CMPUnlocker tool modifies the chip’s behavior by restoring full SM compute throughput and unlocking the HBM2e memory geometry, which was previously restricted by firmware or one-time programmable (OTP) settings. According to technical documentation, the tool also enables access to JTAG registers and, through patched modules, ensures that these changes persist even after system reboots.

Memory Expansion and Hardware Limitations

The main advantage of the tool is the massive increase in available memory. Theoretically, 8-GB models can be expanded to 64 GB, while 10-GB models can reach up to 80 GB. However, achieving these maximum values depends on the quality of the physical silicon chip.

Since the CMP 170HX uses lower-grade A100 chips, NVIDIA has often disabled defective or substandard memory chips at the factory. Consequently, not every card makes the entire memory bank available. Many users find that, depending on their specific hardware bin, they can only reach 32 GB or 40 GB.

Stability also varies depending on the component manufacturer. According to reports, cards with Hynix memory in the 8-GB models tend to be more stable when overclocked to 64 GB. In contrast, Samsung memory chips in the 10-GB models frequently experience instability when unlocked to 80 GB. Memory bandwidth generally ranges between 700 and 800 GB/s per card, though some cards may enforce lower clock speeds to ensure stability.

Performance Limitations for AI Tasks

Although the VRAM expansion is substantial, several hardware bottlenecks limit the CMP 170HX compared to modern AI accelerators. The chip only supports data formats up to INT8 and lacks the FP8, FP6, or FP4 precision found in newer NVIDIA architectures. Its performance is rated at 48 TOPS.

Furthermore, connectivity is a major obstacle. The cards are limited to PCIe Gen 2 x4 speeds. While some users are attempting to achieve x16 Gen 1 speeds or unlock Gen 2 speeds through physical soldering, the standard interface significantly slows down data transfer compared to current GPUs.

Impact and Price Fluctuations

The release of the unlock tool has led to an immediate and drastic shift in the secondary market. Before the tool was released, prices for CMP 170HX cards on platforms like eBay typically ranged between €100 and €200. After it became known that these cards can be repurposed for AI, prices have skyrocketed to between €1,500 and €2,000. According to reports, some buyers are purchasing these cards in large quantities, acquiring up to 100 units at a time.