February 25, 2015, 10:26:42 am
Isn't Lumion rendering based exclusively on CPU?
I think you might mean "..on GPU?"
Not exclusively, but the biggest majority. The performance of how well the card performs in terms of final render output, is also determined by how well the rest of the system supports the GPU to do it's work. The same card placed in two different PC setups will not have the exact same results.
If you were to look at Passmark results, for example the GTX 980, you will see that each of the last 5 Baselines submitted is different, in some cases by large differences. A small part off that difference could be due to differences in manufacture, quality of chips used, better card design etc. The remainder is therefore explained by the rest of the system.