NVIDIA has released their alternate graphics drivers for OS X Yosemite 10.10.5. These are separate from the drivers Apple ships as standard, and should be considered experimental. These drivers have been known to solve OpenCL issues with certain applications, as well as providing better native GPU power management for certain devices.
NOTE: These drivers are currently the only method to get full acceleration for 'Maxwell' graphics cards:...
NVIDIA Releases Alternate Graphics Drivers for 10.10.5 (346.02.03)