Cycles render is different when rendering with GPU I came across a problem which I couldn't find any solution through google. When I render with my GPU, I have a different render than with the CPU.

My CPU is an amd phenom 2 x4 965, the GPU is a R9 390 with blender 2.76
first is cpu second is gpu
I have sharp shadows with cpu and light is very dim with gpu, what could cause this problem?

CPU


GPU
I'm using a HDRI lighting in my scene which is not yet supported in OpenCL. Anyone knows when it will be supported?

Well i just had a look at the supported features page, and it says that HDR float isn't supported yet with opencl 

blender.org/manual/render/cycles/gpu_rendering.html 

"OpenCL: No support for HDR (float) textures at the moment.".