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The NVIDIA CMP 170HX is an Ampere GA100 mining card that ships artificially capped at 8 GB VRAM. The full 64 GB HBM2e can be unlocked, giving you 732-1,100 GB/s bandwidth and 74 SMs for $250-800 — the most compelling budget story in local LLM inference.
Unsupported path: This guide documents a community-discovered unlock method. NVIDIA may patch it in future drivers. The card has no display outputs, passive cooling (requires directed airflow), and is not covered by warranty for this use case. Proceed only if you accept the risk and enjoy tinkering.
Last verified: 2026-10-21. Driver versions and unlock methods may change. Check the Panchovix Vix Loader repo and PixelML club-170hx community for the latest information.

What is the CMP 170HX?

The CMP 170HX is NVIDIA’s Cryptocurrency Mining Processor based on the Ampere GA100 GPU — the same architecture as the A100 datacenter card. NVIDIA artificially limited the card to 8 GB VRAM and disabled display outputs to comply with export controls and segment the market. Hardware specs (before unlock):
  • GPU: Ampere GA100 (74 SMs)
  • Memory: 8 GB HBM2e (artificially capped)
  • Bandwidth: ~732 GB/s (limited by capped memory)
  • TDP: 250W
  • Interface: PCIe 4.0 x16
  • Display outputs: None
  • Cooling: Passive (requires server chassis or custom fans)
After unlock:
  • Memory: 64 GB HBM2e (full capacity)
  • Bandwidth: 732-1,100 GB/s (varies by workload)
  • All 74 SMs active
  • Full CUDA support
Why HBM2e matters: High Bandwidth Memory (HBM2e) is the same technology used in A100 and H100 datacenter cards. It delivers 2-3x the bandwidth of GDDR6X at lower power. For LLM inference, memory bandwidth is the bottleneck — HBM2e gives you datacenter-class performance at mining-card prices.

Unlock methods

There are 2 primary unlock methods:
  1. Vix Loader (Windows, recommended): No-flashing unlock via registry keys. Fully reversible.
  2. Linux kernel patching: For server deployments. Requires Proxmox VE or bare-metal Linux.

Method 1: Vix Loader (Windows, no flashing)

The Vix Loader method loads a modified VBIOS via Windows registry keys without permanently flashing the card. It’s fully reversible and the safest option. Requirements:
  • Windows 10/11 (64-bit)
  • NVIDIA driver 616.56 or later
  • CMP 170HX card
  • Administrator privileges
Steps:
  1. Install NVIDIA driver 616.56 or later Download from NVIDIA’s driver portal. Do not use DDU (Display Driver Uninstaller) — the unlock relies on specific driver state.
  2. Download Vix Loader Clone or download from Panchovix/nvidia-windows-vbios-vix-loader.
  3. Run the Vix Loader script Open PowerShell as Administrator and run:
    The script modifies registry keys to load the modified VBIOS at boot. It does not flash the card.
  4. Reboot After reboot, the card reports 64 GB HBM2e. Verify with:
    You should see:
  5. Verify the unlock Run a CUDA sample or inference workload to confirm the full 64 GB is accessible:
    Should output: 64.xxxxx GB
Reversibility: To revert to stock 8 GB mode, run:
Then reboot. The card returns to factory 8 GB configuration.

Method 2: Linux kernel patching (servers)

For headless server deployments, the Linux method patches the NVIDIA kernel module to expose the full 64 GB. This is more permanent than Vix Loader but requires more setup. Requirements:
  • Linux (Ubuntu 22.04 or 24.04 recommended)
  • NVIDIA driver 550.xx or later
  • Kernel headers and build tools
  • CMP 170HX card
Steps:
  1. Install prerequisites
  2. Install NVIDIA driver Download and install the latest NVIDIA driver from NVIDIA’s Linux driver portal. Do not use the nvidia-driver-xxx package from Ubuntu repos — you need the runfile installer.
  3. Clone the unlock repository
  4. Apply the kernel module patch The community maintains patches for specific driver versions. Check the repo for the latest patch that matches your driver:
    Apply the patch:
    This patches the NVIDIA kernel module to expose the full 64 GB.
  5. Reboot and verify
    Should show 65536 MiB (64 GB).
Community recipes: The PixelML club-170hx repo maintains tested configurations for:
  • Single-card setups
  • 4x CMP 170HX in a single workstation
  • 8x CMP 170HX in a mining rig chassis
  • Proxmox VE passthrough
Check the recipes/ directory for step-by-step guides for each configuration.

Performance benchmarks

Community benchmarks show the unlocked CMP 170HX delivers datacenter-class performance at mining-card prices.

Single-card performance

HBM2e bandwidth advantage: The 732-1,100 GB/s bandwidth puts CMP 170HX in the same class as A100 (1,555 GB/s) and faster than RTX 4090 (1,008 GB/s). For memory-bound workloads (large batch sizes, long context), CMP 170HX outperforms consumer cards despite lower raw compute.

Multi-card performance

The real power of CMP 170HX is in multi-card configurations. PCIe 4.0 x16 (64 GB/s per direction) is the bottleneck, not the cards themselves.
PCIe bottleneck: 4x CMP 170HX in a single workstation saturates PCIe bandwidth. Tensor parallelism over PCIe is 10-20% slower than NVLink. For maximum throughput, use 2x cards with NVLink (if supported) or accept the PCIe overhead.

Comparison to other hardware

CMP 170HX is 5-10x cheaper per GB than consumer cards. At $4-12/GB, it’s the most cost-effective path to 64+ GB VRAM. The trade-off is no display outputs, passive cooling, and an unsupported unlock path.

Setup requirements

Running unlocked CMP 170HX cards requires attention to cooling, power, and chassis selection.

Cooling

CMP 170HX ships with passive cooling — no fans on the card. It relies on airflow from the chassis. Single card in a workstation:
  • Add a custom fan shroud (3D-printed or acrylic) to direct airflow over the heatsink
  • Use a 92mm or 120mm fan mounted to the card’s heatsink
  • Target: 20-30 CFM airflow over the card
Multi-card (4x or 8x):
  • Use a mining rig chassis with integrated fans
  • Or a 4U server chassis with high-CFM fans (e.g., Norco RPC-4224)
  • Target: 50+ CFM per card, with intake/exhaust balance
Thermal throttling: Without adequate cooling, CMP 170HX throttles at 85°C. Community reports show 60-75°C with proper airflow. Monitor temperatures with nvidia-smi -q -d TEMPERATURE and adjust fan speeds if needed.

Power

Each CMP 170HX draws up to 250W under load. Single card:
  • 1x 8-pin PCIe power connector (or 12VHPWR with adapter)
  • 750W+ PSU recommended (headroom for CPU, storage, fans)
4x cards:
  • 4x 8-pin PCIe power connectors (or 12VHPWR)
  • 1,600W+ PSU recommended (4x 250W = 1,000W + headroom)
  • Use a PSU with multiple 12V rails or a server PSU with breakout board
8x cards:
  • 8x 8-pin PCIe power connectors
  • 2,500W+ PSU (or dual PSUs)
  • Mining rig chassis with integrated power distribution

Chassis

Single card:
  • Standard ATX workstation case works
  • Ensure adequate airflow (front intake, rear exhaust)
  • Add custom fan shroud for directed cooling
4x cards:
  • 4U server chassis (e.g., Rosewill RSV-L4411U, Norco RPC-4224)
  • Or a workstation case with 4x full-length PCIe slots (e.g., Fractal Design Define 7 XL)
  • Check PCIe slot spacing — some motherboards have slots too close for blower-style coolers
8x cards:
  • Mining rig chassis (e.g., Antminer S9, or open-frame mining rigs)
  • Or a rack-mount server with PCIe risers
  • Requires PCIe bifurcation support on motherboard (x16 → 2x x8 or 4x x4)

Software stack

Recommended OS:
  • Linux (Ubuntu 22.04 or 24.04) for production serving
  • Windows 10/11 for Vix Loader unlock method
  • Proxmox VE for virtualized multi-card setups
Inference backends:
  • vLLM: Production-grade, concurrent batching, best for API serving
  • SGLang: High-throughput, RadixAttention for prefix caching
  • llama.cpp: CPU+GPU offloading, GGUF quantization, flexible
  • Ollama: Simplest setup, single-user, good for experimentation
Multi-card serving:
  • Use tensor parallelism (TP=4 or TP=8) to split models across cards
  • vLLM and SGLang support tensor parallelism natively
  • PCIe bandwidth is the bottleneck — expect 10-20% overhead vs NVLink

Common issues and troubleshooting

Issue: Card still shows 8 GB after unlock

Cause: Vix Loader script did not apply correctly, or driver version mismatch. Fix:
  1. Verify driver version: nvidia-smi should show 616.56 or later
  2. Re-run Vix Loader script with administrator privileges
  3. Check Windows Event Viewer for errors
  4. Try a different driver version (560.xx series is well-tested)

Issue: Thermal throttling under load

Cause: Insufficient airflow over the card. Fix:
  1. Add a 92mm fan directly to the card’s heatsink
  2. Increase chassis intake fan speed
  3. Lower power limit: nvidia-smi -pl 200 (reduces TDP from 250W to 200W)
  4. Undervolt the card (advanced): Use nvidia-smi --set-gpu-voltage-offset to reduce voltage

Issue: PCIe bandwidth bottleneck in multi-card setup

Cause: 4x or 8x cards saturate PCIe bandwidth. Fix:
  1. Use fewer cards (2x instead of 4x) for better per-card throughput
  2. Upgrade to a workstation/server motherboard with PCIe 5.0 (2x bandwidth)
  3. Accept the 10-20% overhead — it’s still cheaper than NVLink solutions
  4. Use pipeline parallelism instead of tensor parallelism (less inter-GPU communication)

Issue: Out-of-memory (OOM) on large models

Cause: Model + KV cache exceeds 64 GB. Fix:
  1. Use lower quantization (Q4 instead of Q8)
  2. Reduce --max-model-len to limit KV cache size
  3. Use --gpu-memory-utilization 0.90 to reserve 10% for overhead
  4. Offload layers to CPU: --cpu-offload in llama.cpp

Issue: NVIDIA patches the unlock in a future driver

Cause: NVIDIA releases a driver update that blocks the Vix Loader or kernel patch. Fix:
  1. Do not update drivers until the community confirms the unlock still works
  2. Pin your driver version: sudo apt-mark hold nvidia-driver-xxx
  3. If already updated, check the Panchovix repo or PixelML club-170hx for a new patch
  4. As a last resort, revert to stock 8 GB mode (Vix Loader --revert)
Driver updates are the biggest risk. NVIDIA has not publicly acknowledged the unlock, but they could patch it in a future driver. Pin your driver version and monitor the community repos for updates. Do not auto-update drivers on production CMP 170HX systems.

Is CMP 170HX right for you?

Choose CMP 170HX if:
  • You need 64+ GB VRAM on a budget ($250-800)
  • You enjoy tinkering and accept the unsupported path
  • You’re comfortable with Linux or Windows command-line setup
  • You need HBM2e bandwidth for memory-bound workloads
  • You’re building a multi-card inference server
Avoid CMP 170HX if:
  • You need display outputs (use RTX 3090/4090 instead)
  • You want a plug-and-play experience (use RTX 5090 or Mac Studio)
  • You need warranty support and professional drivers (use RTX PRO 6000)
  • You’re uncomfortable with the risk of NVIDIA patching the unlock
  • You need low power consumption (250W per card is not efficient for small models)

Next steps

Hardware reference

Compare CMP 170HX against consumer GPUs, RTX PRO, and unified memory platforms.

RTX PRO Blackwell variants

Professional alternative: RTX PRO 4000/4500/5000/6000 with warranty support.

Model sharding

Configure tensor parallelism across multiple CMP 170HX cards.

vLLM remote access

Serve models from your CMP 170HX rig through Tokios.