Hi!
Boinc does not recognize OpenCL capability on my Nvidia GTS450 GPU.

When i start Boinc there is only one Message regarding the GPU:

...
11.12.2012 20:41:57 | | Local time is UTC +1 hours
11.12.2012 20:41:57 | | NVIDIA GPU 0: GeForce GTS 450 (driver version 306.97, CUDA version 5.0, compute capability 2.1, 1024MB, 8381345MB available, 568 GFLOPS peak)
11.12.2012 20:41:57 | | No general preferences found - using defaults
...

Other people with Nvidia cards also get this message at startup:

NVIDIA GPU 0: GeForce 8400M GS (driver version 306.23, CUDA version 5.0, compute capability 1.1, 128MB, 8380435MB available, 38 GFLOPS peak)
OpenCL: NVIDIA GPU 0: GeForce 8400M GS (driver version 306.23, device version OpenCL 1.0 CUDA, 128MB, 8380435MB available)

The Problem is that OpenCL Projects such as POEM@Home doesn't work:
09.12.2012 19:02:42 | Poem@Home | Requesting new tasks for NVIDIA
09.12.2012 19:02:43 | Poem@Home | Scheduler request completed: got 5 new tasks
09.12.2012 19:02:43 | Poem@Home | [error] Missing coprocessor for task poempp_gpucrystal_1355075903_653427590_0; aborting
09.12.2012 19:02:43 | Poem@Home | [error] Missing coprocessor for task poempp_gpucrystal_1355075905_1199484614_0; aborting
09.12.2012 19:02:43 | Poem@Home | [error] Missing coprocessor for task poempp_gpucrystal_1355075906_1959632453_0; aborting
09.12.2012 19:02:43 | Poem@Home | [error] Missing coprocessor for task poempp_gpucrystal_1355075907_715658007_0; aborting
09.12.2012 19:02:43 | Poem@Home | [error] Missing coprocessor for task poempp_gpucrystal_1355075907_2050856376_0; aborting

But GPU-Z tells me, that OpenCL is active and Lightsmark2.0 is using OpenCL for calculations.
Only Boinc seems not be able to detect OpenCL.

Windows=7Home64
CPU FX-8350, 16GB RAM

I tried this:
Boinc completely new installed (7.0.28)
Geforce-Driver completely new installed (306.97)
The GPU-App of Poem@Home from another user copied on my computer and several app_info.xml from other users that work on their PCs.

GPU-Projects that dont need OpenCL such as Seti@Home or Einstein@Home work fine.

Any further suggestions?

MagicEye04

As the "[error] Missing coprocessor for task poempp_gpucrystal_1355075903_653427590_0;" line shows, BOINC was perfectly capable of detecting the OpenCL at an earlier time. Until something changed, drivers perhaps? Did you install newer drivers?

As that's what it'll come down to. BOINC checks if a certain library file is installed by the drivers, and if it cannot find this, it won't be able to tell that the GPU is OpenCL capable.

All Nvidia GPUs that can do CUDA are OpenCL capable, but it needs to be activated through drivers. So all I can offer you is to uninstall the drivers again, perhaps clean them out with Driver Sweeper, then reinstall them. And if newer drivers still don't give the OpenCL capability, go back to older drivers that obviously did.

---

Where did you get your driver from? From Microsoft?, Dell? or from Nvidia?

The Microsoft supplied driver won't come with any support for OpenCL, and apparently neithier does the Dell supplied driver, you'll only get OpenCL support from drivers direct from Nvidia,

There has also been OpenCL detection problems with Boinc, but normally it has been with an OpenCL device being detected, but then being not used,

Claggy

The PC was set up new last month.
I installed Windows7, then the Nvidia Driver (direct from Nvidia) und then Boinc.
The first weeks i only crunched for seti@home and after a while i tried poem@home but then i got openCL errors.

So it is not possible to set a flag or anything like this in a config file to tell Boinc that there IS openCL ?

I suggest doing as Ageless says and clean out the old drivers.
Driver Fusion is the successor to Driver Sweeper and finds a few more registry entries to clean.
http://treexy.com/products/driver-fusion

The most complete way that I have found:

Uninstall the old drivers from the Control Panel (Programs and Features in Win7)
Reboot as necessary for each driver (audio, graphics, PhysX, etc.)
Run Driver Fusion to clean out the rest of the registry entries
Reboot

Then you might want to try the latest released drivers, 310.70 from Nvidia.

And using a Custom clean install, I never install the Nvidia automatic updater; it often causes problems.