[Discuss] Conflicting Information Regarding Video Memory

[epp at mcom.com]

This PC has an on-board AMD RS780L (Radeon 3000) GPU. The lspci command
is showing it is allocated 256 Mb of RAM. Although the glxinfo
command is displaying the same 256 Mb, it also indicates 'total
available memory' as 765 Mb. I had been contemplating purchasing a
video card for this, but as the only ports inside it are PCI Express
x1, the only video cards I've been able to find have no more than 512
Mb on them.

If 765 Mb is more accurate, then I will leave it as it is, as the card
would override any on-board graphics.

The output from both commands, is below. Thanks in advance for any info.

glxinfo:

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD RS780 (DRM 2.50.0 / 5.8.13-200.fc32.x86_64, LLVM 10.0.1) (0x9616)
    Version: 20.1.9
    Accelerated: yes
    Video memory: 256MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 3.3
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.0
Memory info (GL_ATI_meminfo):
    VBO free memory - total: 255 MB, largest block: 255 MB
    VBO free aux. memory - total: 509 MB, largest block: 509 MB
    Texture free memory - total: 255 MB, largest block: 255 MB
    Texture free aux. memory - total: 509 MB, largest block: 509 MB
    Renderbuffer free memory - total: 255 MB, largest block: 255 MB
    Renderbuffer free aux. memory - total: 509 MB, largest block: 509 MB
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 256 MB
    Total available memory: 765 MB
    Currently available dedicated video memory: 255 MB


lspci:

01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS780L [Radeon 3000] (prog-if 00 [VGA controller])
        Subsystem: Hewlett-Packard Company Device 2ab7
        Flags: bus master, fast devsel, latency 0, IRQ 18, NUMA node 0
        Memory at d0000000 (32-bit, prefetchable) [size=256M]
        I/O ports at c000 [size=256]
        Memory at fe9f0000 (32-bit, non-prefetchable) [size=64K]
        Memory at fe800000 (32-bit, non-prefetchable) [size=1M]
        Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
        Capabilities: <access denied>
        Kernel driver in use: radeon
        Kernel modules: radeon