Request: Smart Access Memory information

[HD7950]

3700X + B450 + RX570

[FONT=monospace][COLOR=#000000]sudo dmesg | grep BAR [/COLOR]
[    0.629031] pci 0000:26:00.0: BAR 0: assigned to efifb
[    2.444113] [drm] Detected VRAM RAM=4096M, BAR=4096M[/FONT]

[FONT=monospace][COLOR=#000000]AMD_DEBUG=info glxinfo | grep vram  [/COLOR]
   vram_size = 4096 MB
   vram_vis_size = 4096 MB
   vram_type = 5
   vram_bit_width = 256
   has_dedicated_vram = 1[/FONT]

[msjyoshi]

Ryzen 2600 + Asrock AB350M-HDV + RX 6800
Disabled CSM (which just altogether disappeared from the bios afterwards) and enabled >4G MMIO

[ 2.034526] [drm] Detected VRAM RAM=16368M, BAR=16384M

vram_size = 16384 MB
vram_vis_size = 16368 MB
vram_type = 9
vram_bit_width = 256
has_dedicated_vram = 1
all_vram_visible = 1

[WDsZvbQuG]

Also had to disable CSM to get to boot normally, otherwise I'd get a constant error "[amdgpu] trn=2 ack should not assert".

System: Kernel: 5.10.4-zen2-1-zen x86_64 bits: 64 compiler: gcc v: 10.2.0
parameters: initrd=\amd-ucode.img initrd=\initramfs-linux-zen.img cryptdevice=/dev/nvme0n1p2:main
root=/dev/mapper/main-root rw lang=de init=/usr/lib/systemd/systemd locale=de_DE.UTF-8 module_blacklist=nouveau
Desktop: KDE Plasma 5.20.5 tk: Qt 5.15.2 wm: kwin_x11 dm: SDDM Distro: Arch Linux
Machine: Type: Desktop Mobo: Micro-Star model: B450 TOMAHAWK MAX (MS-7C02) v: 1.0 serial: <filter> UEFI: American Megatrends
v: 3.A2 date: 12/08/2020
CPU: Info: 6-Core model: AMD Ryzen 5 3600 bits: 64 type: MT MCP arch: Zen 2 family: 17 (23) model-id: 71 (113)
stepping: N/A microcode: 8701021 L2 cache: 3 MiB

AMD_DEBUG=info glxinfo | grep vram
vram_size = 8192 MB
vram_vis_size = 8176 MB
vram_type = 9
vram_bit_width = 256
has_dedicated_vram = 1
all_vram_visible = 1

[Kano]

i7-9700K / Z390 / RX 570:

AMD_DEBUG=info glxinfo | grep vram
vram_size = 4096 MB
vram_vis_size = 4096 MB
vram_type = 5
vram_bit_width = 256
has_dedicated_vram = 1

[deemon]

MSI Tomahawk X570 + 5950X + Vega 64

AMD_DEBUG=info glxinfo | grep vram
vram_size = 8192 MB
vram_vis_size = 8176 MB
vram_type = 6
vram_bit_width = 2048
has_dedicated_vram = 1
all_vram_visible = 1

[aceman]

Hi, I only get vram_vis_size of 256MB while I do have the "Above 4G decoding" visible and enabled in the UEFI BIOS.
This is with Radeon RX560 (4GB VRAM), X399 (Threadripper 1) chipset board and an Asus BIOS.
What should I check more?

I read that one may need some UEFI boot (why???) for it. I do have CSM enabled, as I want a normal boot from MBR and via 'lilo' bootloader.
I could try 'elilo' if it still boots without any EFI partition on the disk.
Thanks

[Girolamo_Cavazzoni]

It won‘t work with CSM enabled.

[aceman]

It won‘t work with CSM enabled.

Ok, but will it still be possible to boot with plain 'lilo' ?

And what does the method to boot the OS have to do with the capabilities of the graphics card?

[Girolamo_Cavazzoni]

It‘s not about the method of booting, at least it doesn’t matter which bootloader is used, just about in what state the firmware is when booting. There are certainly reasons why BIOS mode can‘t do it.

[agd5f]

Legacy sbios modes put all MMIO apertures under 4GB for 32 bit compatibility. You need an extended MMIO aperture above 4GB in order to resize the BARs.