32-bit vs. 64-bit Ubuntu 13.04 Linux Performance
For the disk benchmarks, there isn't too much to see when comparing the 64-bit and 32-bit results.
When running OpenArena 0.8.8, which has both 32-bit and 64-bit binaries, the 64-bit Ubuntu Linux setup had a slight edge in performance.
Xonotic at 1024 x 768 had a drop in performance with the 32-bit Ubuntu installation.
With a higher resolution, 64-bit Ubuntu edged out in a slightly better state for the Xonotic OpenGL first person shooter.