P6 Revisited

When is someone going to write an "emperor's new clothes" story about Intel's P6 chip? If I compile a word processor with a 32-bit compiler, it still does byte manipulation, and if it uses the string manipulation instructions for string searches, it will have target bytes in registers, etc. Why should such software speed up on a P6 if compiled with a 32-bit compiler as compared to a 16-bit compiler?

I think the P6 team really blew it. The Pentium is the last x86 chip to give great gains in existing software without recompilation. It will be interesting to see if Intel can convince people to drop their Pentiums for P6s. I wouldn't.

Bob Morris
morris@sce.carleton.ca

We've published two stories (plus a sidebar) on the P6's problems with 16-bit software (September and October BYTE). The fact is, our own benchmarks -- as well as o ther widely used benchmarks, such as SysMark -- confirm that the P6 does a very good job of running 32-bit software. I don't think the P6 team "blew it." I do think that Intel misjudged how long it would take for Microsoft to ship a mainstream 32-bit OS, and also how much old 16-bit code would be left in that "32-bit" OS.

The P6 is optimized for 32-bit code, not a specific flavor of 32-bit code, and the software industry -- pushed by Microsoft's Win32 API -- is moving to 32 bits independently of the P6's characteristics. The P6's product life will probably extend to the end of this decade. I can't fault Intel for designing the chip with the future in mind. -- Tom R. Halfhill, senior editor

For an update on BYTE benchmarks and the P6 chip, see "BYTEmark Bug Bashed" in this issue's News & Views section. -- Eds.