Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

Could someone help me read this information better, I am suspicious of this line: Memory at d0000000 (64-bit, prefetchable) [size=256M]

My video card is supposed to have 1GB of memory, however I'm not sure if this output reflects that or if I'm looking at the wrong thing?

01:00.0 VGA compatible controller: ATI Technologies Inc Cypress [Radeon HD 5800 Series] (prog-if 00 [VGA controller])
    Subsystem: ATI Technologies Inc Device 0b00
    Flags: bus master, fast devsel, latency 0, IRQ 44
    Memory at d0000000 (64-bit, prefetchable) [size=256M]
    Memory at fbee0000 (64-bit, non-prefetchable) [size=128K]
    I/O ports at d000 [size=256]
    Expansion ROM at fbec0000 [disabled] [size=128K]
    Capabilities: [50] Power Management version 3
    Capabilities: [58] Express Legacy Endpoint, MSI 00
    Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
    Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
    Capabilities: [150] Advanced Error Reporting
    Kernel driver in use: fglrx_pci
    Kernel modules: fglrx, radeon
share|improve this question
add comment

2 Answers

I wouldn't worry about this in that it happens to the best of us. My card has 1536 MB of onboard video RAM yet this is what lspci shows:

03:00.0 VGA compatible controller: nVidia Corporation GF110 [GeForce GTX 580] (rev a1) (prog-if 00 [VGA controller])
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at f9000000 (32-bit, non-prefetchable) [size=16M]
        Memory at e0000000 (64-bit, prefetchable) [size=128M]
        Memory at ee000000 (64-bit, prefetchable) [size=32M]
        I/O ports at 7f00 [size=128]
        [virtual] Expansion ROM at e8000000 [disabled] [size=512K]
        Capabilities: <access denied>
        Kernel driver in use: nvidia
        Kernel modules: nvidia_current, nvidia_current_updates, nouveau, nvidiafb

There are filed bugs and a billion and five forum threads (all around the internet, not just Ubuntu) about this.

I'm personally of the opinion that this is a lspci bug (or feature omission) and that it doesn't actaully effect anything negatively. For nvidia users, I trust nvidia-settings (or Catalyst for the AMD/ATI users) when it reports the value correctly:

enter image description here


X also knows:

oli@bert:~$ grep -i memory /var/log/Xorg.0.log
[    26.504] (--) NVIDIA(0): Memory: 1572864 kBytes
[    26.585] (II) NVIDIA: Using 3072.00 MB of virtual memory for indirect memory
[    26.777] (==) NVIDIA(0): Disabling shared memory pixmaps
share|improve this answer
add comment

Me the same, I think 256M means mega but not megabytes, I think it means we have 256 mega(1024x1024) blocks of 64 bit addresable memory words thats 8 bytes so:

256M * 8b = 2048Mb (2Gb)

that's double as expected now, so it must mean that of those 64 bits is a trick and only 32 bits are really in physical memory

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.