I seriously doubt that new card is going to make much difference. I've got massive props in Poser and for that matter my last scene was a huge scene. It had one massive building prop, at least 50 small and large props, 9 different fully dressed figures ( a mix of V5, V3, M3 and M4) with large body textures and of course they had hair :) The figures did wear either dresses, tunics with pants and boots or a full armor.

My Poser is still very responsive and I don't have the GPU or VRAM you've got, not even close to it. My graphics card is a ATI HD 7450m with 1GB..... they system is a laptop with an i5 2450m and 6Gb of RAM. OpenGL is set on the highest settings and everything is smooth and resposive. I even can use harware shading without a problem, everything is still responsive, not as smooth, but stiill good and the sure not crawling along, but there is a slight noticable lag now. It's save to say that if my laptop can handle all of that, yours should be able to handle a lot more and a lot easier.

I don't have that loft, but looking at it my latest scene comes pretty close. I do have a similar appartment scene and I've got no problem with that either.

I'd say there is something wrong with your settings if you can't handle that with all the power you've got now already. Is there some way to monitor the VRAM your current card is using? I seriously doubt that loft with a few figures will need 4Gb at all. I know most Poser stuff is fine with 1GB of Vram, since a lot of vendors do not have the latest hardware at all, a lot of them use older stuff.

Just looking at what the loft all works with and I do see Poser 7 and DS3..... if it works in that it sure isn't going to eat op lot's of Vram at all.

Artwork and 3DToons items, create the perfect place for you toon and other figures!

http://www.renderosity.com/mod/bcs/index.php?vendor=23722

Due to the childish TOS changes, I'm not allowed to link to my other products outside of Rendo anymore :(

Food for thought.....
https://www.youtube.com/watch?v=pYZw0dfLmLk