Wasnt there a bit of hoo-harr about differences in clock speeds, between retail and oem. Only with radeon cards.
I cant remember which has the faster clock, but ATI kept quiet about this, and folks was in uproar cos there vid card was not clocked at the speed stated.
Dont know if things have changed, but if I were you I'd look very closely into this.
P3 800e @ 1 Gig with Alpha PEP66
256M PC133 Crucial
Iiyama VisionMaster Pro450
Corsair PC2700 cas2