CPU and GPU produce different results
Open, ConfirmedPublic

Description

System Information
ArchLinux
NVidia GTX 680
CPU Phenom II X4 965

Blender Version
2.79

Short description of error

I was experimenting with the hybrid GPU/CPU rendering when I noticed this. Rendering on GPU produces a different tonal quality than rendering on CPU. Using the development hybrid renderer results in tiles rendered on CPU being noticably different than those rendered on the GPU. There are image samples at https://blenderartists.org/forum/showthread.php?439146-2-8-Branch-update-with-Cycles-CPU-GPGPU-rendering-together&p=3262986&viewfull=1#post3262986{F1263496}

Exact steps for others to reproduce the error
Render GPU in one slot, CPU in another, and switch to see the difference

Details

Type
Bug

Thanks for report.
This is the problematic scene that Roken posted in other report:

Sergey Sharybin (sergey) triaged this task as Confirmed priority.Mon, Dec 4, 11:04 AM
Sergey Sharybin (sergey) claimed this task.

Can confirm the issue, didn't look into details yet. Needs investigation! Will have a look soon unless someone else from Cycles team steals this report :)