corsair xms4000 question

grabbed some of these, CMX4000PT (1 gig, 2x512)

i was reading review, all the reviewers has rev. 1 samples, which had 4ns ram

the ones i got are rev. 2.1, anyone know what kind of ram these are running? aida says 4.2ns (?) but if anyone knows let me know. i dont wanna take off the heatspreaders, so you get the idea.

thanks.