May 12, 2013, 02:27:12 am
Welcome to Lumion.
In general a better GPU will only provide faster output, especially noticed in rendering video animations. The same rendering processes apply to any GPU used.
However, there is a point where your card with limited memory will not be able to support more complex scenes, and so may start having issues or not work properly at all. In addition effects added to a scene such as GI, planar reflections and in combination with spotlights, does require a good/high performing GPU, so you may find you become limited in the range of images you can produce.
Also, more recent cards have much bigger VRAM, and so can also support more and higher resolution textures. Better textures help to improve the quality of the final image.