Having the same problem with my Ultra. Cinerenders using AC25 used up many more cores than what AC26 (official ARM M1 designed) appears to support.Don't know why AC26 doesn't offer a MAX_CORE for Cinerender.

I have an Ultra 128MB and I have to say it's like butter compared to my 2014 Intel MAC 4GHz.I've noticed that, for quick and dirty photo renderings, IradLegacy produces very quick renderings with 20 cores. In that setting, the GI phase doesn't take a...