In 2.9 betas, there’s no obvious indication that Optix rendering is being used (If you select Optix in prefs, then that’s what Cycles seems to use.) In 2.8 it explicitely stated Optix as the render engine. Is this by design, or something yet to be fixed?
Optix seems to either be slightly underlit compared with Cycles, or the brightest and darkest pixels are closer together across the spectrum. Is this also a bug, or by design?
I can’t share the renders I’m testing with, unfortunately. They are themed, and I’m saving for next month before I post. However, if no-one has noticed similar, I’m sure I can throw a scene together that will demonstrate the difference.
Having said that, Optix even on a 1070 (i.e. non RTX) is rendering about twice as fast with everything else the same.