Ubuntu 16.04 LTS Is Deprecating AMD's fglrx (Catalyst) replacing with amd-gpupro

I had a couple of RX 460s arrive recently so I thought I'd see if I could get them crunching using my distro of choice - PCLinuxOS.  I keep a local copy of the PCLOS repo and a quick check showed that the FOSS driver amdgpu was there but nothing for the proprietary driver.  I decided to do a fresh install of the latest available live USB (Jan 2017) on a retired machine (Q6600 CPU) just to see if I could work out how to crunch on an RX 460.  All my machines have three disk partitions, root, swap and /home.  Reinstalling the OS doesn't touch any of the user files or configuration so is quite quick and relatively painless.  After installation, I added the FOSS driver from the repo, as it wasn't on the live USB.  After configuring the machine to use the amdgpu driver, a reboot encountered no problems.

PCLinuxOS packages are in rpm format so I decided to download the Red Hat version of AMDGPU-PRO 16.60 with a view to seeing how the OpenCL stuff was packaged.  The first pleasant surprise was the new --compute option in the install script which kindly identified what sub-set of packages was needed just for OpenCL computing.  So I extracted the packages in question and moved the contents to /opt/amdgpu-pro/.  There were three sub-dirs - bin/ (clinfo), lib64/ (shared libs) and share/ (some docs).  There were two other bits in directories lib/ and etc/ for installation elsewhere - /lib/udev/rules.d/91-drm_pro-modeset.rules and /etc/OpenCL/vendors/amdocl64.icd.

After moving all this stuff into place, I ran ldd on clinfo to see what libs that app would be needing.  The only one not found was libamdocl64.so.  A check on the contents of /opt/amdocl-pro/lib64 showed it was there so I realised I just needed to add /opt/amdocl-pro/lib64 to $LD_LIBRARY_PATH.  I was then quite excited to see clinfo run without error and produce a whole bunch of output :-).

So now onto BOINC.  When the client starts, at least for V7.2.42 which I'm using, GPU detection depends on the client finding the OpenCL libs as /usr/lib64/libOpenCL.so.  With the old fglrx driver, PCLOS installs everything under /usr/lib/fglrx-current/.  I've always needed to add a symbolic link in /usr/lib64 pointing to fglrx-current/libOpenCL.so.  I presumed I would need to do a similar thing for the new OpenCL stuff in /opt/amdgpu-pro/lib64.  The contents of the .icd file that I'd installed in /etc above pointed to the OpenCL lib being libamdocl64.so so I just created the link libOpenCL.so -> libamdocl64.so.

I have a small shell script that launches BOINC.  It checks a couple of things and launches the client as a daemon.  So I modified the script on the test machine to prefix the command to launch the client with LD_LIBRARY_PATH=/opt/amdgpu-pro/lib64.  This machine had never been restarted after a storm last December had taken out the entire fleet.  I had progressively brought most hosts with GPUs back to crunching but had retired most of rest - including 6 similar Q6600 CPU machines.   I knew there would be expired CPU tasks to clean up but otherwise the BOINC installation should all be there ready to go.

So I just inserted the new GPU in the PCI-e slot and used the supplied 6-pin <-> molex power cable to get GPU power from the existing 300W PSU (270W available at 12V).  I knew from previous experience that these PSUs will run a HD7850 in a similar setup so the new card should use less and so should be fine.  I'll get around to doing some proper power measurements at some point :-).

When I was running the live USB to reinstall PCLOS in the root partition, I mounted /home temporarily and added all the apps and other files needed (eg. app_config.xml for x2 GPU crunching) to the existing BOINC stuff.  I also edited client_state.xml to add the tag <dont_request_more_work/> so that BOINC wouldn't try to fetch anything when first launched.

BOINC launched just fine with warnings about the 'long overdue' tasks.  I was very pleased to see the following in the event log

... Data directory: /home/gary/BOINC
... OpenCL: AMD/ATI GPU 0: Baffin (driver version 2264.10, device version OpenCL 1.2 AMD-APP
    (2264.10), 2001MB, 2001MB available, 1366 GFLOPS peak)
... OpenCL CPU: Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz (OpenCL driver vendor:
    Advanced Micro Devices, Inc., driver version 2264.10 (sse2), device version OpenCL 1.2
    AMD-APP (2264.10))

After aborting the expired CPU tasks, I allowed new work and watched as BOINC downloaded both CPU and GPU tasks.  It was very nice to see GPU crunching take off.  I only had one GPU task initially and it took a few retries to get some more so I had the opportunity to get a feel for a single task crunch time - probably would have ended around 24 mins.  It has been crunching for the best part of 2 days now with no errors or invalids.  A look at the list of validated tasks shows close to 100 so far, with each pair finishing in about 36-37 mins, so a nice improvement over the single task crunch time.  Based on the results so far, the theoretical RAC should be around 270K - not too shabby for a $US100 upgrade to a previously retired host :-).