July 06, 2012, 10:04:11 am
The 7950 has a pretty high benchmark. The 690 is a dual gpu and you will not get any performace boost, probably less, the 680 is benchmarked higher than the 7950 but only by about 10%. Unless its tested against your scene it would be hard for anyone to answer how much of a speed increase or not you would get. If you can afford, it would be interesting for everyone here to know what impact the change of hardware had in a real scene case.
You could try changing the time scale on clips so that Lumion is not rendering the full time length at 30 frames but something less, and that will help with overall rendering time. You can then add in some interpolated in-between frames in a video editor.
Alternatively reduce other render settings, maybe starting with reducing the Extra Frame Edge, depending on scene redner requirements.