Here are some results I did on a test compiling MySQL 5.0.41 with Sun Studio 12 vs GCC 3.4.5. This was on a x4100:

Single threaded test:

GCC 3.4.5:

# time make
real 8m36.944s
user 6m53.556s
sys 1m24.685s

Sun Studio 12:

# time dmake
real 6m54.376s
user 9m34.147s
sys 2m3.422s

Conclusion: Sun Studio 12 owns.

Here are some other results of a threaded compile with Sun Studio 12 just to show off:

# time dmake -j 8
real 6m11.507s
user 9m44.306s
sys 2m17.845s

# time dmake -j 4
real 5m52.583s
user 9m52.261s
sys 2m16.401s

4 threads is the sweet spot which is the number of CPU’s in the system.