Probably because I'm an old hot-rodder, I tend to push Poser to the limit, making complex scenes using a lot of SFX, and rendering at large pixel dimensions.  Whereas P6 and P7 would crash if pushed over the edge, I have noticed that now Poser slows down, but never crashes.  I don't know what has been improved about the memory management, but something has been improved.  Galadriel has 12Gb of RAM and I have repeatedly pushed Poser to the point where total sytem usage tops 12,000Mb, but instead of crashing, now Poser seems to approach the memory limit asymptotically, i.e., it nudges up close to the without ever overstepping the limit. 

Overnight renders of wallpapers are common;  rendering a series of PNGs for a forty second video clip might be 4-5 days running three or four computers simultaneously.  I've never had an issue with Poser (6, 7, Pro, 8) being open for a long time.

Right now Galadriel is doing a test render of a (new freebie! ^^) elven boat with an experimental wake.  She has everything I could think of engaged - IDL, quadratic falloff detail lights, gamma correction, ray-traced shadows, AO on select parts with invaginations, reflection, translucence, refraction, and lots of displacement.  Might be done about sundown.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5