What has more bang/buck for rending in cycles, ram or CPU? Will jumping from 16 to 32GB ram make a huge difference in CPU rendering time, or am I better off buying an upgraded CPU and staying at 16? I normally use paired GPUs, but so far, cycles can’t do hair on GPU. Any suggestions would be greatly appreciated - I’m definitely not a hardware guy.
i7-2600k @ 3.4
16 GB ram
EVGA GTX 570+GTX 580
RAM amount makes no difference at all in rendering time, unless you run out of it (at which point your system will start paging memory to the harddrive and become almost unusable).
As of Blender 2.68, there is hair support with GPU rendering.
As Zal said, if you’re not running out, throwing more RAM into your system won’t change squat.
Hair is indeed enabled on the GPU in 2.68, but don’t expect any furry characters or fields of grass. Hair in Blender is currently a memory hog, and I’ve had final characters who creeped above 10GB because of their hair in close up shots.