Command per clock?

I updated the bios on my DFI Ultra Infinity... and a new feature was added called command per clock, the two options are enabled and disabled... enabled and it won't boot over 220 FSB, disabled and it will do 250+ So what does it do? and if its useful... how can I get it to work at high FSB?

The discussion in this thread:
http://www.ocforums.com/showthread.php?s=&threadid=277226&highlight=cpc*
make it sound like DRAM CMD Rate on via-based boards. For an explanation of DRAM Command Rate, go to this page:
http://www.lostcircuits.com/advice/bios2/7b.shtml