The 265 flavours of Intel's Pentium 4

SOMEONE SHOWED US an Intel document the other day which contained a revision history for the Pentium 4, which launched back in Q4 2000.

Intel uses some of the letters of the alphabet to distinguish the different microprocessors it makes. For example, A is the Pentium II, B, the mobile Intel Pentium II, C the Celeron, D the Pentium II Xeon, and so on. Z is the mobile Intel Pentium 4 processor with 533MHz system bus and this means that Intel has run out of letters of the alphabet.

The same document also shows the list of bugs for the Pentium 4, most of which have been fixed, and some of which have workarounds if they haven't been fixed.

Never mind that for the moment. The fact is that there's been a staggering 265 versions of the Pentium 4 in its different packagings. That's due to a combination of sockets, cache, clock speeds, the process used and the steppings of the chip's core. Then there's boxed Pentium 4s with fans, with heatsinks, without fans, and the like.

First came the 423 pin socket, then the 478 pin socket, then came the Extreme Edition in the 478 pin socket. Soon there will be more processors coming along too, all with different S-Specs. An S-Spec is Intel's five digit code to identify products which includes core speed, cache size, package type and the rest.

The table is far too big to reproduce here, but the point is that somewhere in Intel's 80,000+ strong organisation there are people who have to look at these tables, sort out these different processors, and put them in the right place.

According to the document, each unique processor stepping and package combo also has an associated micocode update, and when that's applied it's a pukka Pentium 4.

It's all pretty impressive stuff. µ