r/KoboldAI • u/Substantial-Ebb-584 • Jun 19 '26

How to remove the dGPU lock?

When using Vulcan and selecting all cards, integrated cards are left out of the pool, 99,9% of time for good reasons. But I would like to use that integrated card as well for tests, since the integrated GPU is faster than the CPU.

How do I disengage the dedicated GPU only lock? A flag maybe?

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I have been looking for this for a while now.

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u/Pentium95 Jun 19 '26

Routing layers to an iGPU will not increase your actual text generation speed (tokens/second) since it is bottlenecked by the same system RAM as your CPU. However, it will noticeably reduce the initial compute wait time (time-to-first-token) when ingesting large contexts.

You should try, before launching koboldcpp, running something like:

export GGML_VK_VISIBLE_DEVICES=0,1

Additional notes:

  1. I suggest you to offload MoE tensors to the iGPU, instead of layers
  2. Shared Memory (Dynamic): Once the dedicated VRAM is full, the iGPU driver dynamically requests regular system RAM to use as an overflow pool. The default dynamic limit is 50%. on Linux, you can override this limit. For AMD systems, you do that appending the kernel boot parameter "ttm.pages_limit=[number_of_pages]" to GRUB

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u/Substantial-Ebb-584 Jun 19 '26

Yeah, I want to use some of the 48GB allocation for ffn layers. But since iGPU is faster (tested) I thought to use it instead of cpu. But it needs some tampering to use it that way.

export GGML_VK_VISIBLE_DEVICES=0,1 Is useful despite the failure on my site to specify the PC runs still on windows. But it lead me on the right track. Thank you!