Open CL performance degradation

Hi everyone!

I noticed long time ago that last driver versions compute much slower than old.

version - time (sec)
332.35 - 68.608
337.88 - 67.532
344.48 - 75.355
353.62 - 103.565
362.00 - 103.971
385.69 - 101.64

332.35, 337.88, 344.48 - Open CL 1.1, others - Open CL 1.2.

As you can see: the device has lost 50% (100*(101.64-67.532)/67.532) of performance.

Here is the test project:
http://iberezansky.net/files/2DGPUDecartAutoResolution.zip
It is gas dynamic contact border (a shock wave interacts with a He bubble) computation with WENO5, WENO3 schemes.

The device is Geforce GTX 870M.

Best regards,
Ivan.