DGX Spark GB10 shows only ~56GB VRAM inside AI Workbench (128GB expected)

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Hi,

I’m running a DGX Spark with a GB10 GPU (128GB VRAM).

Inside the AI Workbench environment, nvidia-smi shows:

  • FB Memory Usage: N/A
  • Total/Used/Reserved memory: N/A
  • MIG Mode: N/A
  • Effective VRAM only ~56GB
  • vLLM fails to start because it requires >100GB free memory

On the host machine (outside Workbench), the GPU shows the full 128GB normally.

This suggests that Workbench is using a virtual GPU (vGPU / SR-IOV) profile instead of giving full GPU passthrough.

Support asked me to post this question here.

How can I configure AI Workbench / DGX Spark to expose the full 128GB GPU memory to containers?

can you please post the docker command used to launch the ai workbench container?

Where to get the relevant instructions? thanks

Hi, can you provide a screenshot of your nvidia-smi output using AI Workbench? Due to the DGX Spark having unified memory, nvidia-smi cannot report on GPU memory usage so it is unclear what number you are seeing that only shows 56GB

Could you please simply tell me the correct command to see that the available is 128G? thanks.

It is unclear what you are seeing in the first place. nvidia-smi cannot show memory usage due to the unified memory architecture so we do not understand where you are seeing this 56GB number so we are asking for more details

This is invalid. I can run models using vLLM on docker with high-utilization. I suggest you start using llama.cpp over ollama, it’s much more performant.

Sample with vLLM: Running nvidia/Nemotron-Nano-VL-12B-V2-NVFP4-QAD on your spark

Performance numbers, using containers with high-utilization with 1 or 2 sparks:

@dzhao05 Are you still running into this issue? If so can you give more details?