GPU Upgrade for Second LIfe

So my wife's B-Day is tomorrow and I plan to upgrade her vid card for Second Life.

Some of the threads on Second life here were pretty dated so I was hoping for some updated info.

Currenty she's using a rig I build about 6 months ago based on an Athlon II x4, gigabyte 770 mobo and an XFX 4850 1GB.

It does pretty well as is. But the problem with Second Life is that highly populated areas really bog down perfomance. Is this more of an CPU intensive game since a lot of the content is downloaded?

I was thinking about spoiling her with a 5870 because theres one on sale in a local store. But if it's not really going to change much I wouldnt bother.

the rig screams FPS around 80-100 in unpopulated areas, but as low as 10-15 is dance clubs where theres 25+ avatars with all the attachments and stuff on them.

and SL users out here with some input? CPU Upgrade or GPU?

Thanks!

I played on Second life awhile ago, and it seemed to be more based on CPU processes rather than be a GPU intensive game/hobby.

But it may have changed somewhat from my experiance on it, The 4850 1GB seems to be quite a good card anyways, ive opted for Nvidia on my part, so someone with more experiance may be able to offer more support than i can, but i would personally put the game down to more of a CPU based game rather than a GPU intensive one.