Those tests was made using default kernel specs.
It would be nice, for comparison, to customize the kernel , and using the awesomeness of CGROUPS:
1 - allocate process into groups with specific memory usage, I/O usage, swapness levels;
2 - exclusive cores for the 3D processes.
3 - higher cpu shares for the 3D processes.
All the nice stuff you can do with CGROUPS.
One thing is testing the default spec of ubuntu, other is tuning and testing again. Tuning both of the systems to make another benchmark.
Not a single mention to cgroups in that benchmark article.