Decrease AMD iGPU vram allocation without the BIOS

mraf61-i6556 · 2023-09-26 20:51:44

Hello everyone, as you know all HP puts most basic BIOS setting on their laptops, so mine didn't have option to adjust vRAM size...

In short, I have 8GB of RAM in my laptop, and the iGPU take about 2GB of it,

I want to decrease that if possible even to 512MB, since I'm not gaming on this laptop at all...

Is this possible to do with Linux OS only

seth · 2023-09-27 07:13:54

modinfo amdgpu | grep -E 'gtt|gart'

but if the RAM is shortened in the e820 output already (dmesg | grep -iE 'e820|memory') that won't help either.

mraf61-i6556 · 2023-09-27 13:50:54

seth wrote:

modinfo amdgpu | grep -E 'gtt|gart'
but if the RAM is shortened in the e820 output already (dmesg | grep -iE 'e820|memory') that won't help either.

This is command out put looks like Linux assign 2GB to it

parm:           gartsize:Size of kernel GART to setup in megabytes (32, 64, etc., -1=auto) (uint)
parm:           gttsize:Size of the GTT userspace domain in megabytes (-1 = auto) (int)
parm:           smu_memory_pool_size:reserve gtt for smu debug usage, 0 = disable,0x1 = 256Mbyte, 0x2 = 512Mbyte, 0x4 = 1 Gbyte, 0x8 = 2GByte (uint)

dmesg | grep -iE 'e820|memory'

[    1.163120] Non-volatile memory driver v1.3
[    1.242129] Freeing initrd memory: 38168K
[    1.674956] Freeing unused decrypted memory: 2036K
[    1.675505] Freeing unused kernel image (initmem) memory: 3348K
[    6.360861] amdgpu 0000:02:00.0: amdgpu: Trusted Memory Zone (TMZ) feature enabled
[    6.361513] [drm] amdgpu: 2048M of VRAM memory ready
[    6.361517] [drm] amdgpu: 3072M of GTT memory ready.
[    6.588558] amdgpu: HMM registered 2048MB device memory

Last edited by mraf61-i6556 (2023-09-27 14:41:34)

seth · 2023-09-27 14:33:27

I know the output - the idea was to try to control the VRAM assignment through this.
Why are there no e820 records in your dmesg?
Please post your complete system journal for the boot:

sudo journalctl -b | curl -F 'file=@-' 0x0.st

mraf61-i6556 · 2023-09-27 14:36:34

seth wrote:

I know the output - the idea was to try to control the VRAM assignment through this.
Why are there no e820 records in your dmesg?
Please post your complete system journal for the boot:
sudo journalctl -b | curl -F 'file=@-' 0x0.st

here it is :-

https://0x0.st/HVfp.txt

Last edited by mraf61-i6556 (2023-09-27 14:39:38)

seth · 2023-09-27 15:30:54

dmesg probably overflew?

Sep 27 16:37:26 archlinux kernel: Memory: 5826688K/6168456K available (16384K kernel code, 2120K rwdata, 12780K rodata, 3348K init, 3984K bss, 341508K reserved, 0K cma-reserved)

which roughly matches

Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009ffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x0000000000100000-0x0000000009ecffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x000000000a000000-0x000000000a1fffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x000000000a20b000-0x00000000d809ffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x00000000dda62000-0x00000000deffffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x0000000100000000-0x000000019effffff] usable
Sep 27 16:37:26 archlinux kernel: BIOS-e820: [mem 0x000000021f000000-0x000000021f33ffff] usable

(I skipped the details) - the UEFI/BIOS/Firmware gives the OS ~6GB of RAM, if you want more, you need to ask the BIOS.

I've never tried this, but maybe https://wiki.archlinux.org/title/Swap_on_video_RAM can help you out.
Notice the caveat and try to stabilize that w/ amdgpu.vramlimit (check the modinfo)

mraf61-i6556 · 2023-09-27 15:39:19

seth wrote:

dmesg probably overflew?
(I skipped the details) - the UEFI/BIOS/Firmware gives the OS ~6GB of RAM, if you want more, you need to ask the BIOS.
Notice the caveat and try to stabilize that w/ amdgpu.vramlimit (check the modinfo)

Unfortunately, this is an HP laptop and almost no usable BIOS options specially for vRAM, that why I open thread here and other place.

seth wrote:

I've never tried this, but maybe https://wiki.archlinux.org/title/Swap_on_video_RAM can help you out.

For now, I'm trying to use it as SWAP it will be good enough for my use case (some light VM's) to have extra 1.5GB ..

Arch Linux

#1 2023-09-26 20:51:44

Decrease AMD iGPU vram allocation without the BIOS

#2 2023-09-27 07:13:54

Re: Decrease AMD iGPU vram allocation without the BIOS

#3 2023-09-27 13:50:54

Re: Decrease AMD iGPU vram allocation without the BIOS

#4 2023-09-27 14:33:27

Re: Decrease AMD iGPU vram allocation without the BIOS

#5 2023-09-27 14:36:34

Re: Decrease AMD iGPU vram allocation without the BIOS

#6 2023-09-27 15:30:54

Re: Decrease AMD iGPU vram allocation without the BIOS

#7 2023-09-27 15:39:19

Re: Decrease AMD iGPU vram allocation without the BIOS

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