Issue#

AMD 8845HS internal GPU can use RAM as VRAM, but the linux kernel by default will only allocate 50% of total RAM due to safety concern.

This is too conservative and a waste of RAM just sitting there.

We would like to find a balance between system stability and utilization of the RAM.

Before We Start#

pve vm view

Calculate maximum RAM you want to used as VRAM

Typically we keep 8GB RAM as system RAM to keep it stable, you can adjust based on your needs.

So in this case

$64GB - 8GB = 56GB$

$([size~in~GB] * 1024 * 1024) / 4.096$

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sudo nano /etc/default/grub

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GRUB_CMDLINE_LINUX_DEFAULT="amdttm.pages_limit=<setting_value> amdttm.page_pool_size=<setting_value>"

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sudo update-grub

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sudo reboot now

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sudo dmesg | grep -E "amdgpu: .*VRAM|amdgpu: .*GTT"

You should see something like this (my dmesg log has be cleared out, use journalctl instead) validation

Now you have

$2GB + 58GB = 60GB$

of usable VRAM

you can use it to run large LLM model, or run multiple LLM model, etc