By eva2000 both memory have same chips.. i have OCZ PC4000EB and runs flawlessly (not forsale heh).. do a search for PC4000EB on this forum
both should easily hit 250-255mhz -/+ 5-10mhz
Also i saw u posted on XS that u got ur mem to 280mhz? or around that with 2.66v lol.