I'm not on a MAC, but I've been squeezing P6 hard for the last two days, running back to back scenes with different hair models on V3 loaded with way too many morphs. I loaded BV hair and rendered it successfully at 2560 x 1920. I think the P5 dynamic hair that I just loaded is taking P6 down though. Still I got eleven renders out of P6 in a row. I can't figure out P6 though. Some days it dies before I get a foot out the door and the next day, it acts (almost) as stable as P5. Only thing I can recommend is trying again with a very simple scene, ie no background graphics, just the character and the hair and try again. Maybe even start off with an untextured character. And a footnote, the P5 hair finally loaded :-)