Part Number	Frequency	Features	BIOS	PCB	Notes
Intel Pentium III
80525PY450512 BX80525U450512	450	4.5 x 100 MHz, Katmai	The latest	B1 / B3 / C
80525PY500512 BX80525U500512	500	5 x 100 MHz, Katmai	The latest	B1 / B3 / C
80526PY500256	500E	5 x 100 MHz, Coppermine	The latest	B1 / B3 / C
80525PY550512 BX80525U550512	550	5.5 x 100 MHz, Katmai	The latest	B1 / B3 / C
80526PY550256 BX80526U550256	550E	5.5 x 100 MHz, Coppermine	The latest	B1 / B3 / C
80525PY600512 BX80525U600512	600	6 x 100 MHz, Katmai	The latest	B1 / B3 / C
80526PY600256 BX80526PY600256	600E	6 x 100 MHz, Coppermine	The latest	B1 / B3 / C
80526PY650256 BX80526U650256	650	6.5 x 100 MHz, Coppermine	The latest	B1 / B3 / C
80526PY700256 BX80526U700256	700	7 x 100 MHz, Coppermine	The latest	B1 / B3 / C

Part numbers are not supplied by motherboard manufacturers. We use best guess approach to determine part numbers based on CPU model, frequency and features. In some cases our guess may be incorrect or incomplete. Please always verify part numbers before committing to buying the CPU.