Benchmarks Of GCC 4.5.0 Compiler Performance
There is not much change between the GCC releases with the 3000 Fall test in the Bullet Physics Engine.
Bullet's 1000 stack test may be a tad slower with GCC 4.5.
The 1000 convex test in this major open-source physics engine has definitely regressed under GCC 4.5.
The convex trimesh test is also showing slower performance with the GCC 4.5 binaries.