All current Intel Celeron processors sport several product codes on each processor, but we're only concerned with the S-Spec Number, Assembly Lot Tracking Number, and the country of assembly.
A closeup of the Celeron 366
From the Intel® Celeron™ Processor Specification Update:
S-Spec Number is a five digit code used to identify products. Products are differentiated by their unique characteristics, e.g., core speed, L2 cache size, package type, etc.
There are 4 different Celeron 366 versions, each with a different S-Spec Number.
SL376: SEPP OEM
SL37Q: SEPP Retail Boxed
SL36C: PPGA OEM
SL35S: PPGA Retail Boxed
We went out of our way to get an OEM PPGA version with the SL36C S-Spec Number. The retail box PPGA version might be just as overclockable, but we're not sure yet. (Vendors have a hard time testing sealed processors.) If you've had success overclocking an SEPP or retail boxed PPGA version, let us know on our new FS Overclocking Message Board.
The first 4 digits of the Assembly Lot Tracking Number will tell you the CPU's country of assembly and the week it was produced. The first digit tells you the country of assembly, L or 9 for Malaysia and 0 for Costa Rica. The second digit is the last number of the year of manufacture. If the second digit is an 8 you have a SEPP version that's probably not very overclockable. Intel didn't start making the Celeron 366 PPGA until first quarter 1999.
The third and fourth digits are the week of manufacture. Our Celerons were manufactured in week 25. We're not sure when the Celerons started getting fast, but we only started hearing about the super Celerons a month ago. We'll guess Intel started churning them out sometime between late April and early June which roughly translates to somewhere between week 15 and week 22.
Country of Origin
Not much to say here. Most Celerons are manufactured in Malaysia or Costa Rica. Our Celerons are Malaysian, and all the Celeron 366 PPGA's we've seen also have the Malay tag.