Hi there

I've 20GB installed and my largest scene can take up to 5GB RAM and when rendering I'm close to 9-10GB,but my scene consist from Stonemason scene and he using very large textures and plus other props from TrueForm like Bedroom and usually I'm using 2-3 V4 heavily morphed with SSS textures and what I've check'd usually textures are ranging from 2k to 4k and several clothing and hairs etc and due this my scene can take so much RAM,but on HDD is around 600-800MB,just shame Poser doesn't support instancing or some sort instancing,yes I know Game Dev have poly reduction

I've got 20GB RAM,but I think I will need soon upgrade to more RAM which means new MB and new CPU,8GB is OK,if you are not planning larger scenes,but I would upgrade to more RAM,RAM is not expensive there

Hope this help 

Thanks,Jura