Part Number	Frequency	Features	BIOS	PCB	Notes
Intel Pentium II
80522PX233512 80522PX233512EC B80522P233512	233 MHz		Any	Any
80522PX233512 80522PX233512EC B80522P233512	233 MHz	Slot 1	Any	Any
80522PX266512 B80522P266512 80522PX266512EC B80522P266512E 80523PX266512 80523PX266512PE B80523P266512E	266 MHz		Any	Any
80522PX266512 B80522P266512 80522PX266512EC B80522P266512E 80523PX266512 80523PX266512PE B80523P266512E	266 MHz	Slot 1	Any	Any
80522PX300512 80522PX300512EC B80522P300512E 80523PX300512PE B80523P300512E2	300 MHz		Any	Any
80522PX300512 80522PX300512EC B80522P300512E 80523PX300512PE B80523P300512E2	300 MHz	Slot 1	Any	Any
80523PX333512 80523PX333512PE B80523P333512E	333 MHz		Any	Any
80523PX333512 80523PX333512PE B80523P333512E	333 MHz	Slot 1	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		Any	Any
80525PY450512 BX80525U450512	450 MHz	slot1	Any	Any
80525PY500512 BX80525U500512	500 MHz		Any	Any
80525PY500512 BX80525U500512	500 MHz	slot1	Any	Any
80525PY550512 BX80525U550512	550 MHz		Any	Any
80525PY550512 BX80525U550512	550 MHz	slot1	Any	Any
80525PY600512 BX80525U600512	600 MHz		Any	Any
80525PY600512 BX80525U600512	600 MHz	slot1	Any	Any

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.