Part Number	Frequency	Features	BIOS	PCB	Notes
Intel Pentium II
80522PX233512 80522PX233512EC B80522P233512	233 MHz		Any	Any
80522PX266512 B80522P266512 80522PX266512EC B80522P266512E 80523PX266512 80523PX266512PE B80523P266512E	266 MHz		Any	Any
80522PX300512 80522PX300512EC B80522P300512E 80523PX300512PE B80523P300512E2	300 MHz		Any	Any
80523PX333512 80523PX333512PE B80523P333512E	333 MHz		Any	Any
80523PY350512 80523PY350512PE B80523P350512E BX80523U350512E	350 MHz		Any	Any
80523PY400512 80523PY400512PE B80523P400512E BX80523U400512E	400 MHz		Any	Any
80523PY450512 80523PY450512PE B80523P450512E BX80523U450512E	450 MHz		Any	Any
Intel Pentium III
80525PY450512 BX80525U450512	450 MHz	slot1	1013	Any
80525PY500512 BX80525U500512	500 MHz	slot1	1013	Any
80525PY550512 BX80525U550512	550 MHz	slot1	1013	Any
80526PY550256 BX80526U550256	550E MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY550256 BX80526F550256	550E MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80525PY600512 BX80525U600512	600 MHz	slot1	1014.001	Any
RB80526PY600256 BX80526F600256	600 MHz	socket370 with S370-DL	1014.001	Any
80526PY600256 BX80526PY600256	600E MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY600256 BX80526F600256	600E MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80526PY650256 BX80526U650256	650 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY650256 BX80526F667256	650 MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80526PY700256 BX80526U700256	700 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY700256 BX80526F700256	700 MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80526PY750256 BX80526U750256	750 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY750256 BX80526F750256	750 MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80526PY800256 BX80526H800256	800 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
RB80526PY800256 BX80526F800256E	800 MHz	socket370 with S370-DL	1014.001	1.06*	the later shipment of the same PCB version
80526PY850256 BX80526U850256	850 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
	900 MHz	slot1	1014.001	1.06*	the later shipment of the same PCB version
80526PY1000256 BX80526H1000256	1.0 GHz	slot1	1014.001	1.06*	the later shipment of the same PCB version

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.