Just a heads up...

I recently got these errors (pasted below), including "postponed" message for GPU tasks, on a Windows 10 v1803 PC, that has 3 GPUs: GTX 970, GTX 660 Ti, GTX 660 Ti, with NVIDIA 397.31 drivers.

When I restarted BOINC, it did not see the GPUs at all (CUDA nor OpenCL!)
Also, the NVIDIA system tray icon said "update available", and GeForce Experience said "Driver not found".
When I restarted the PC, everything was fine again, including BOINC GPU detection, and tasks running successfully.

From my experience, and additional research that I've done, I believe:
The NVIDIA 397.31 drivers have a problem "staying installed/detected" on Windows, and NVIDIA is working on it. Restart the PC as a workaround.

Running on device number: 0
Priority of worker thread raised successfully
Priority of process adjusted successfully, below normal priority class used
WARNING: boinc_get_opencl_ids failed with code -1
Error: Getting Platforms. (clGetPlatformsIDs)
BOINC assigns device 0
WARNING: BOINC failed to provide OpenCL device, using own enumeration abilities
ERROR: OpenCL kernel/call 'clGetDeviceIDs (second call)' call failed (-32) in file ..\..\..\src\GPU_lock.cpp near line 1310.
Waiting 30 sec before restart...

What you are describing is symptomatic of MS having installed their version of the nVidia driver which does not have the computational stuff included.

The solution is to get a clean set of drivers from the nVidia website and then do a "clean" installation - which may require a reboot or two. Then turn OFF all Windows hardware driver updates (sadly Windows 10 is infamous for turning this back on again...)

---

Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

I'm telling you, this wasn't a problem on any previous latest driver.
So, even if it Windows Update installing the same driver on top of the existing one, it's something that NVIDIA used to prevent (on latest drivers), but is having trouble preventing (with this latest driver).

This is a 397.31 driver bug, NVIDIA is aware, and in the meantime, GPU projects will have users with this problem.

Note: I did confirm that OpenCL.dll was correctly in the System32 folder, even when I had the problem earlier, for what that's worth.

Regards,
Jacob

397.55 supposedly fixes this issue.

Knowledgebase article:
http://nvidia.custhelp.com/app/answers/detail/a_id/4661

Driver feedback:
https://forums.geforce.com/default/topic/1051755/geforce-drivers/announcing-geforce-hotfix-driver-397-55/