Ok after rereading around I got my answer
Mac Pro 1,1 16GB Ram 1 x 5770 = 75 secs
Mac Pro 1,1 16GB RAM 2 x 5770 = 53 secs
Mac Pro 1,1 16GB RAM 1 x GTX 660 = 182 sec (more than 2x slower)
i4770 3.4Ghz CPU, Z87X MB, 16GB RAM 2 x 5770 = 31 secs
people with a single R9 270x = around...