There are 2 tasks that would require volunteer to do:
1) To determine NV drivers range that suport SIGNALS_ON_GPU OpenCL MB build.
2) To determine NV drivers range that support correct operation of usual OpenCL MB build.
As one can see both tasks require drivers reinstallation (cause different drivers versions needs trial).
If you able and interesting in doing such work please PM me. I'll send links to special binaries appropriate for this test.