Intel Pentium® II, III and Celeron Processors
Please refer to the notes below to differentiate between processor types.

  INTEL PENTIUM II 233 MHz (SLOT 1 - SEC)
  INTEL PENTIUM II 266 MHz (SLOT 1 - SEC)
  INTEL PENTIUM II 300 MHz (SLOT 1 - SEC)
  INTEL PENTIUM II 400 MHz (SLOT 1 - SEC)
  INTEL PENTIUM II 450 MHz (SLOT 1 - SEC)
  INTEL CELERON 300A MHz (SLOT 1 - SEC)
  INTEL CELERON 400 MHz (PPGA)
  BOXED INTEL CELERON 433 MHz (PPGA)
  BOXED INTEL CELERON 466 MHz (PPGA)
  BOXED INTEL CELERON 500 MHz (PPGA)
  BOXED INTEL CELERON 533 MHz (PPGA)
  BOXED INTEL PENT III 500E MHz (FC-PGA)
  BOXED INTEL PENT III 550 MHz (FC-PGA)
  BOXED INTEL PENT III 550E MHz (FC-PGA)
  BOXED INTEL PENT III 600E MHz (FC-PGA)
  BOXED INTEL PENT III 600EB MHz (FC-PGA)
  BOXED INTEL PENT III 650 MHz (FC-PGA)
  BOXED INTEL PENT III 667 MHz (FC-PGA)
  BOXED INTEL PENT III 700 MHz (FC-PGA)
  BOXED INTEL PENT III 733 MHz (FC-PGA)
  BOXED INTEL PENT III 750 MHz (FC-PGA)
  BOXED INTEL PENT III 450 MHz (SECC2)
  BOXED INTEL PENT III 500 MHz (SECC2) *
    BOXED INTEL PENT III 533B MHz (SECC2)
  BOXED INTEL PENT III 533EB MHz (SECC2) *
  BOXED INTEL PENT III 533EB MHz (SECC2)
  BOXED INTEL PENT III 550 MHz (SECC2) *
  BOXED INTEL PENT III 550 MHz (SECC2)
  BOXED INTEL PENT III 600 MHz (SECC2)
  BOXED INTEL PENT III 600B MHz (SECC2)
  BOXED INTEL PENT III 600E MHz (SECC2) *
  BOXED INTEL PENT III 600E MHz (SECC2)
  BOXED INTEL PENT III 600EB MHz (SECC2) *
  BOXED INTEL PENT III 600EB MHz (SECC2)
  BOXED INTEL PENT III 650 MHz (SECC2) *
  BOXED INTEL PENT III 650 MHz (SECC2)
  BOXED INTEL PENT III 667 MHz (SECC2) *
  BOXED INTEL PENT III 667 MHz (SECC2)
  BOXED INTEL PENT III 700 MHz (SECC2) *
  BOXED INTEL PENT III 700 MHz (SECC2)
  BOXED INTEL PENT III 733 MHz (SECC2) *
  BOXED INTEL PENT III 733 MHz (SECC2)
  BOXED INTEL PENT III 750 MHz (SECC2) *
  BOXED INTEL PENT III 750 MHz (SECC2)
  BOXED INTEL PENT III 800 MHz (SECC2) *
  BOXED INTEL PENT III 800 MHz (SECC2)
  BOXED INTEL PENT III 800EB MHz(SECC2) *
  BOXED INTEL PENT III 800EB MHz (SECC2)
  BOXED INTEL PENT III 866 MHz (SECC2) *
  BOXED INTEL PENT III 866 MHz (SECC2)
  BOXED INTEL PENT III 500 MHz ZEON 512k
  BOXED INTEL PENT III 500 MHz ZEON 1 MB
  BOXED INTEL PENT III 500 MHz ZEON 2 MB
  BOXED INTEL PENT III 550 MHz ZEON 512k
  BOXED INTEL PENT III 550 MHz ZEON 1 MB
  BOXED INTEL PENT III 550 MHz ZEON 2 MB

 

* = OEM Version

Note #1: Different Pentium® III processors that share the same core speed in MHz are identified using special codes:

E = 0.18 micron manufacturing process
B = 133 MHz system bus speed

*These letter designators are only used when two or more processors share the same core speed but differ in manufacturing process and/or bus speed.

As an example:

600 (SECC2)  without the designator(s) would indicate that it had a 100 MHz bus speed and was manufactured using the 0.25 micron die process.

600B (SECC2) with the "B" designator would indicate that it had a 133 MHz bus speed and was manufactured using the 0.25 micron die process.

600EB (SECC2) with both the "E" and "B" designators would indicate that it has a bus speed of 133 MHz and was manufactured using the 0.18 micron die process.

Note #2: Unlike the Pentium® II processors that came "boxed" and "unboxed (OEM)" all Pentium® III processors,  both the FC-PGA and SECC2, come in boxed form and are referred to as "boxed". The difference is that the retail version comes with the Intel fan and heat-sink mounted, while the OEM version does not.