HP 1821-3451 - Intel Pentium Pro processor - 166MHz (P6, 512KB Level-2 cache) - Does not include heat sink Retail
HP 1821-3450 - Intel Pentium Pro processor - 180MHz (P6, 256KB Level-2 cache) - Does not include heat sink Retail
HP 1821-3452 - Intel Pentium Pro processor - 200MHz (P6, 512KB Level-2 cache) - Does not include heat sink - (Part of D4867A) Retail
HP D4975-63000 - Intel Pentium II processor - 266MHz (Klamath, 66MHz front side bus, 512KB Level-2 cache, Slot 1, ECC) - Does not include heat sink Retail
