PC Hardware in a Nutshell, 3rd Edition

Intel Pentium 5?

Intel and AMD play a constant game of leapfrog. The introduction of the Opteron/Athlon 64 almost demanded that Intel introduce a new processor of its own. That processor is the Prescott-core Pentium, due in the fourth quarter of 2003, which Intel may or may not call the Pentium 5.

On balance, we think Intel will decide to name their new processor the Pentium 5, both for marketing reasons and for technical reasons. From a marketing standpoint, Intel would clearly like to counter the Opteron and Athlon processors with a newly-named processor of their own. From a technical standpoint, the improvements in architecture and instruction set are sufficient to justify the Pentium 5 name for the Prescott-core processor.

No matter what Intel chooses to call this processor, it is a significant improvement on the current Northwood-core Pentium 4. Relative to current Northwood-core processors, the Prescott-core processors increase L1 cache size, boost L2 cache from 512 KB to 1024 KB (matching the new AMD processors), and increase pipeline depth to enable higher core frequencies.

Just those enhancements would have made life difficult for the new AMD processors. But a more significant enhancement lurks within Prescott. The Prescott New Instructions (PNI) are 13 new instructions that extend the SSE and SSE2 multimedia instruction sets used by earlier Intel processors. In particular, three of the new PNI instructions are worth noting. One adds support for AV encoding—as opposed to AV ...