most processors are 1/3 rds. Early pentiums are 133, 166, 200 (actually 199) etc. That still applies to todays processors. A 3ghz processor is actually 2999.99999999999999 (repeater), a 1.8ghz processor is 1799.999999999999999 (repeater). Well thats what the chip was designed for. Some mobos actually round it up or down 1 mhz or overclockers might change it.