2 Replies Latest reply on Feb 2, 2018 2:45 PM by theminingking

    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






          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
        • Re: 8GB RX580 Global Memory Size reports only 6GB??

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

          • Re: 8GB RX580 Global Memory Size reports only 6GB??

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


               sudo lspci -v -s 01:00.0




                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.




               sudo dmesg | grep drm




                [ 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.