Hi !
According to an intel developer, a technique described here may be used to improve CPU performance up to 150% using SMM. It tweaks voltage, frequency and unlock processor pipelines.
In the same article another hint is given to enable hardware RAM data compression, that allow a 2x compression ratio of the RAM at almost no cost. I tested it, with only a small addon in my OS startup, my 1GB memory was seen as 2GB: impressive !
Unfortunately both techniques only works on Intel branded CPU starting with the pentium generation.
Decypher the SMM and improve CPU performance
Re:Decypher the SMM and improve CPU performance
Nice try. 
Every good solution is obvious once you've found it.