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theminingking
Journeyman III

8GB RX580 Global Memory Size reports only 6GB??

Something seems off...

if I execute:

    ethminer -G --list-devices

It reports:

    [0] [0] Ellesmere 
        CL_DEVICE_TYPE: GPU
        CL_DEVICE_GLOBAL_MEM_SIZE: 5975805952
        CL_DEVICE_MAX_MEM_ALLOC_SIZE: 4244635648
        CL_DEVICE_MAX_WORK_GROUP_SIZE: 256

Similarly,

    /opt/amdgpu-pro/bin/clinfo

reports

    ...
    Global memory size: 5975805952
    Constant buffer size: 4244635648
    ...

These cards are supposed to have 8GB of onboard memory. I'd expect something like this:

    CL_DEVICE_GLOBAL_MEM_SIZE: 8451543040

Any insight?

  • Ubuntu 16.04
  • AMDGPU-PRO 17.40
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2 Replies
meister_rm
Journeyman III

Have you checked on another application to see the reporting size? I would use GPU-Z or similar program and see what it reports.

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theminingking
Journeyman III

I don't know about `gpu-z` on Ubuntu, but I did try a few things:

   sudo lspci -v -s 01:00.0

Reports

    01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 67df (rev e7) (prog-if 00 [VGA controller])

        Subsystem: ASUSTeK Computer Inc. Device 0521

        Flags: bus master, fast devsel, latency 0, IRQ 16

        Memory at c0000000 (64-bit, prefetchable) [size=256M]

        Memory at d0000000 (64-bit, prefetchable) [size=2M]

        I/O ports at e000 [size=256]

        Memory at dfe00000 (32-bit, non-prefetchable) [size=256K]

        Expansion ROM at 000c0000 [disabled] [size=128K]

        Capabilities: [48] Vendor Specific Information: Len=08 <?>

        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

        Capabilities: [200] #15

        Capabilities: [270] #19

        Capabilities: [2b0] Address Translation Service (ATS)

        Capabilities: [2c0] #13

        Capabilities: [2d0] #1b

        Capabilities: [320] Latency Tolerance Reporting

        Capabilities: [328] Alternative Routing-ID Interpretation (ARI)

        Capabilities: [370] L1 PM Substates

        Kernel driver in use: amdgpu

        Kernel modules: amdgpu

`sudo lshw -class display` reports similar information, except in hex.

Interestingly,

   sudo dmesg | grep drm

Reports

    [ 9.252075] [drm] amdgpu: 8192M of VRAM memory ready

    [ 9.252075] [drm] amdgpu: 8192M of GTT memory ready.

This post describes a similar problem:

amd graphics - RX 580 8GB not using more than 2GB memory - Ask Ubuntu

But of course in his case, he's only getting use out of 2GB while I'm getting 6GB.

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