the celeron would have a 100MHz FSB Vs the 133FSB on the P3
note that there are two versions of the celeron @ 1GHz going around (Coppermine-128 , 0.18m) & (Tualatin-256 , 0.13) , 128KB L2 Cache vs L2 256KB Cache , the Tualatin-256 is FC-PGA2 making it incompatible with older Socket 370 Motherboards.