October 27, 2013, 11:35:29 pm
Should you be wanting to compare against the GTX 780 or the Titan? Or is it price based?
The ATI R9 290X has only just been released, and apart from the R9 290X and R9 290 the rest are just re-branded existing 7000 series cards (as were the GTX 760/770). There's plenty of reviews.
How well they actually compare until we see real user benchmarks is something of a guess. One review has the 7990 better than the R9, so it depends, and the R9 290X is top of range. The GTX 780 outperforms the 7990 in
Passmark: Videocard Benchmarks, but whether that holds true and whether that applies to Lumion is too early to say. But you are welcome to let us know what results you get if your do go for the R9

.
The GTX tends to do better with Lumion because its closer to standards.
Only thing you can be certain of, (all things being equal) todays tech will be faster than yesterdays.