Quote - Well, I'm on Vista so can't be much help.  I don't get any slowing down or crashing but here's some sample render times - just a small 640x400 at Final render setting:

no clouds     11 secs
spectral1 'Storm Clouds'   51 secs
spectral2 'Dark Cumulus' 2m 57 secs
non-spectral clouds
Aggregated Cumulus  13 secs
Swirly Cumulus (volumetric) 13 secs

Gill,

Thanks for letting me know.

If you could followup and let me know what your system specs are and if you are using Vue 7.4 it would help. I am still in the process of trouble shooting this with them.

It has got to be something strange because I checked with one other person that has the same Apple Mac Pro 2008 I do with the NVIDIA 8800GT and he too is having the same problem.

It may not be on other Apple models, graphic cards, etc.

I am sending more data in I have collected from other posters on some sites later this week.

Jeff

Development on: Mac Pro 2008, Duel-Boot OS - Snow Leopard 10.6.6 & Windows 7 Ultimate 64bit, 2 x 2.8 GHz Quad-Core Intel Xeon , 10GB 800 MHz DDR2 RAM, NVIDIA GeForce 8800GT.