OS X 10.8.2, C8.5-172, very slow renders and crash
I recently got an iMac and have been using Carrara on it. This has been very nice because it renders four times faster than my old system, but I have encountered a problem with my latest scene.
The scene isn't particularly complex with two props, m4, v4 and conforming clothing. And dynamic hair for grass -- but that's nothing compared to a recent scene with numerous objects, high counts for dynamic hair (three sets), etc., etc. The current scene rendered fine when I did tests to see how it looked, but when I went to do a final render I noticed it was going very slowly -- the CPU was at 25% utilization! (reported as 200%, out of 800% due to four core with hyper threading). Normally it is around 750% utilization so I looked for causes and tweaked the render settings.
There's no disk access going on with plenty of free memory. No other processes are taking up much CPU. I went back to the previous settings and with other tweaking managed to get a little more utilization (reported as 250%). Well, I let it run and did some editing in a text file so I wasn't watching and don't know how far it got, but not very far based on time elapsed, when Carrara crashed.
I can't really see anything to either cause a low CPU utilization render or to induce a crash. I've been on 10.8.2 for nearly as long as I've had the computer and have rendered for ~8 days solid (batch of multiple scenes) without mishap. So I'm at a loss.
I'll be trying the render again in a bit, but it will take a while due to the slowness to discover anything. Anyone else on OS X experiencing these sort of issues?