OR v2.25 Standalone with EVGA GTX 980 Ti SC+@VRAM 3505MHz forced running Win 10 x64.
Render time: 172h10min - my GTX 980 Ti SC+ gets still ZERO fails after all images!
PMC kernel default settings except:
-244750 spp*
-66-diffuse and 100-specular max depth
-path term. 0.000 (new)
-10k-reject
-caustic blur 0.00
-parallelism 1
Materials:
-prism with dispersion 0.036 and ior 1.407 (dispersion and ior are funny - lol xD)
-torus knot with dispersion 0.006 and ior 1.509
-2 mirrors (big circular tape and 1/4 of ball with the light is inside)
Imager settings are same - see my 4th post except exposure 4.000 instead of ISO and vignette 0.000.
* - I want 256k-spp but Windows 10 had forced BADLY auto-reboot about updates due to OR program affected.
Therefore, Microsoft is very stupid, 
