CentOS - Jun 2007 - freq scaling on centos 5

In the old centos 4 we had cpuspeed and we could send
a SIGUSR1 to it so the CPU would run at max speed.

In centos 5 cpuspeed is not running. (although running with cpuspeed -C 
will go full speed)
what is the correct way now in centos 5 to on the fly say run at full 
speed then sometime
later tell it to drop back down? I have no process to signal any more.

Jerry