Request: Smart Access Memory information

[jojo7887]

Ryzen 1700X + Asus PRIME B350M-A (BIOS 5603 / Latest) + RX 5500 XT. I looked for the BAR option in bios but nowhere to be found, my bios was outdated and I've updated it to latest to see if it enables it, no difference though.

AMD_DEBUG=info glxinfo | grep vram
vram_size = 8192 MB
vram_vis_size = 256 MB
vram_type = 9
vram_bit_width = 128
has_dedicated_vram = 1

EDIT: Wasn't aware BAR requires CSM to be turned off and mine was on. Turned it off in Bios but no difference. Seems Asus didn't enable it at all for this particular model.

Also checked out my new system with Asus Prime B550M-A (Bios version 1401) + 5800X and I can enable the "Above 4G / BAR Resize" option, can't go in further as I'm running Nvidia GPU on that system.

[agd5f]

Ryzen 3900X + Asrock X570M Pro4 + Radeon RX 5500

vram_size = 8192 MB
vram_vis_size = 256 MB
vram_type = 9
vram_bit_width = 128
has_dedicated_vram = 1

There is "above 4G decoding" in my BIOS but the option greyed out. Maybe I should flash my BIOS from 1.80 to latest version first.

Try disabling CSM or making sure you are using UEFI rather than legacy mode.

[addei]

Intel I5-9600k + Asus ROG Strix Z390-F + AMD Radeon RX 6800
In the bios "above 4G decoding" enabled. Does this mean I can also benefit from these optimizations?

[FONT=monospace][COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_size = 16384 MB [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_vis_size = 16368 MB [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_type = 9 [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_bit_width = 256 [/COLOR]
has_dedicated_[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000] = 1[/COLOR][/FONT]

[ObiWan]

3900X with Gigabyte X570 + Powercolor RX 5700XT
Above 4G decoding is enabled in BIOS

[FONT=monospace][COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_size = 8192 MB [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_vis_size = 256 MB [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_type = 9 [/COLOR]
[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_bit_width = 256 [/COLOR]
has_dedicated_[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000] = 1[/COLOR][/FONT]

on lspci it does claim to support it, so something must be blocking it ....

[FONT=monospace][COLOR=#000000]     Capabilities: [200 v1] Physical Resizable BAR [/COLOR]
               BAR 0: current size: 256MB, supported: 256MB 512MB 1GB 2GB 4GB 8GB
               BAR 2: current size: 2MB, supported: 2MB 4MB 8MB 16MB 32MB 64MB 128MB 256MB[/FONT]

Edit:
Updated BIOS to F31o, redid all my settings, the first boot no change, but after the second boot:

> 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

[bridgman]

Even if you modify the data with the host cpu, you'd need to pull the data out of the card's memory over pcie into the cpu and back again; pcie cycles are *slow*, I cannot imagine why someone would do that on a per-frame basis (then again I'm no graphics person and have desinged my last pieces of hardware 10 years ago).

If the update involves changing a small portion of a large buffer then with large BAR the CPU can simply write the new data - no need to read back.

[plasticbomb1986]

On the latest Beta bios for my ASUS ROG Crosshair VII Hero WIFI, the 4g option is present in the new PCI Subsystem menu, and can be enabled (BIOS version 4001), on Bios 3103 and before the option is not present, and its disabled by default, so no resizable BAR support on them.

AMD Ryzen 7 3800XT
Asus ROG Crosshair VII Hero WiFi
32GB DDR4 3200MHZ
2*AMD VEGA 64
ARCHLINUX Kernel 5.9.12-zen1-1-zen

$ 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
$ sudo dmesg | grep BAR=
[sudo] password for ******:
[ 2.503440] [drm] Detected VRAM RAM=8176M, BAR=8192M
[ 3.109110] [drm] Detected VRAM RAM=8176M, BAR=8192M

[brainpower]

% sudo dmidecode -t0 -t2 | grep -E 'Product|Version'
Version: 2812
Product Name: TUF GAMING X570-PLUS
Version: Rev X.0x

% grep name /proc/cpuinfo | uniq
model name : AMD Ryzen 9 3900X 12-Core Processor

% AMD_DEBUG=info glxinfo | grep -E 'vram|name'
name of display: :0
name = POLARIS10
marketing_name = AMD Radeon (TM) RX 480 Graphics
vram_size = 8192 MB
vram_vis_size = 8192 MB
vram_type = 5
vram_bit_width = 256
has_dedicated_vram = 1

% dmesg | grep BAR=
[ 2.224378] [drm] Detected VRAM RAM=8192M, BAR=8192M

Above 4G decoding is Enabled in UEFI SETUP.

[Lemonzest]

Does this only work for power of 2 VRAM sizes? I have enabled Above 4GB Decoding in my UEFI (Ryzen 7 1700/MSI X370 Gaming Pro Carbon) and it is not working? I'm getting the following with a PowerColor RedDevil 5600 XT

[ 0.644969] pci 0000:2a:00.0: BAR 0: assigned to efifb
[ 5.840337] amdgpu 0000:2a:00.0: BAR 2: releasing [mem 0x7ff0000000-0x7ff01fffff 64bit pref]
[ 5.840338] amdgpu 0000:2a:00.0: BAR 0: releasing [mem 0x7fe0000000-0x7fefffffff 64bit pref]
[ 5.840426] [drm:amdgpu_device_resize_fb_bar [amdgpu]] *ERROR* Problem resizing BAR0 (-22).
[ 5.840432] amdgpu 0000:2a:00.0: BAR 0: assigned [mem 0x7fe0000000-0x7fefffffff 64bit pref]
[ 5.840439] amdgpu 0000:2a:00.0: BAR 2: assigned [mem 0x7ff0000000-0x7ff01fffff 64bit pref]
[ 5.840461] [drm] Detected VRAM RAM=6128M, BAR=256M

vram_size = 6144 MB
vram_vis_size = 256 MB
vram_type = 9
vram_bit_width = 192
has_dedicated_vram = 1
all_vram_visible = 0

[Xeno]

Ryzen 3 3100; MSI B450A-PRO MAX; Saphire Radeon RX480 Nitro+, BIOS rev: 7B86vM7
Fedora 33, kernel 5.9.11

vram_size = 8192 MB
vram_vis_size = 8192 MB
vram_type = 5
vram_bit_width = 256
has_dedicated_vram = 1

[drm] Detected VRAM RAM=8192M, BAR=8192M

[theboomboomcars]

[FONT=monospace][COLOR=#5454ff][B]Machine:   Type:[/B][/COLOR][COLOR=#000000] Desktop [/COLOR][COLOR=#5454ff][B]Mobo:[/B][/COLOR][COLOR=#000000] BIOSTAR [/COLOR][COLOR=#5454ff][B]model:[/B][/COLOR][COLOR=#000000] X370GT5 [/COLOR][COLOR=#5454ff][B]UEFI:[/B][/COLOR][COLOR=#000000] American Megatrends [/COLOR][COLOR=#5454ff][B]v:[/B][/COLOR][COLOR=#000000] 5.14 [/COLOR][COLOR=#5454ff][B]date:[/B][/COLOR][COLOR=#000000] 12/03/2019  [/COLOR]
[COLOR=#5454ff][B]CPU:       Info:[/B][/COLOR][COLOR=#000000] 8-Core [/COLOR][COLOR=#5454ff][B]model:[/B][/COLOR][COLOR=#000000] AMD Ryzen 7 1700 [/COLOR][COLOR=#5454ff][B]bits:[/B][/COLOR][COLOR=#000000] 64 [/COLOR][COLOR=#5454ff][B]type:[/B][/COLOR][COLOR=#000000] MT MCP [/COLOR][COLOR=#5454ff][B]L2 cache:[/B][/COLOR][COLOR=#000000] 4096 KiB  [/COLOR]
         
[COLOR=#5454ff][B]Graphics:  Device-1:[/B][/COLOR][COLOR=#000000] Advanced Micro Devices [AMD/ATI] Navi 14 [Radeon RX 5500/5500M / Pro 5500M] [/COLOR][COLOR=#5454ff][B]driver:[/B][/COLOR][COLOR=#000000] amdgpu [/COLOR][COLOR=#5454ff][B]v:[/B][/COLOR][COLOR=#000000] kernel  [/COLOR]
          [COLOR=#5454ff][B]Display:[/B][/COLOR][COLOR=#000000] x11 [/COLOR][COLOR=#5454ff][B]server:[/B][/COLOR][COLOR=#000000] X.Org 1.20.10 [/COLOR][COLOR=#5454ff][B]driver:[/B][/COLOR][COLOR=#000000] amdgpu,ati [/COLOR][COLOR=#5454ff][B]unloaded:[/B][/COLOR][COLOR=#000000] modesetting,radeon [/COLOR][COLOR=#5454ff][B]resolution:[/B][/COLOR][COLOR=#000000] 3840x2160~60Hz  [/COLOR]
          [COLOR=#5454ff][B]OpenGL:[/B][/COLOR][COLOR=#5454ff][B]renderer:[/B][/COLOR][COLOR=#000000] Radeon RX 5500 XT (NAVI14 DRM 3.39.0 5.9.11-3-MANJARO LLVM 11.0.0) [/COLOR][COLOR=#5454ff][B]v:[/B][/COLOR][COLOR=#000000] 4.6 Mesa 20.2.3 [/COLOR][/FONT]

[FONT=monospace][COLOR=#000000]AMD_DEBUG=info glxinfo | grep vram  [/COLOR]
   [COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_size = 8192 MB [/COLOR]
   [COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_vis_size = 8176 MB [/COLOR]
   [COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_type = 9 [/COLOR]
   [COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000]_bit_width = 128 [/COLOR]
   has_dedicated_[COLOR=#ff5454][B]vram[/B][/COLOR][COLOR=#000000] = 1[/COLOR][/FONT]