The other day I got my hand on a dual-GPU Mac Pro (ATI x1900, Quad-2.66 GHz, 10GB Ram) and quickly benchmarked two data sets with the new Equalizer polygonal renderer.
It’s pretty amazing what happens when you try to visualize more data than you can fit on the GPU. Apparently the drivers don’t do a very good job of paging the data in and out of GPU memory.
The first model I’ve benchmarked has 10 million triangles, rendered with Display Lists. On two cards there is a speedup of 2.3 (1.7->3.9 FPS) when dividing the work in screen-space, and a speedup of 3.77 (6.4 FPS) when dividing the database.
A small-ish data set of one million triangles showed, as expected, almost no scalability, running around 20 FPS.
When I find the time, I’ll do extensive testing and will write a proper white paper on the pitfalls of using a multi-GPU Mac Pro. Things I’ll cover are multi-view rendering for display walls (single- and multi-threaded), more data sets and a baseline using PCIe x16 (For the test above, both cards did run at PCIe x8).