PENT III

12/4/99

Pentium III - An Intel CPU released in Late February 1999. The internal code name during development was 'Katmai'. The Pentium III is similar to the Pentium II. It was released initially at 450 and 500 MHz. 550MHz and 600MHz Versions followed. Regular steps were made up to 1GHz which had severe availability problems. A 1133 MHz Pentium-3 was released in August, 2000 in a highly questionable state. It was recalled after about 4 weeks.

The Pentium III is a 2 volt device apparently released in both a SEC1 (Slot 1) or SEC2 (Slot2) configuration. It has a (split?) 32K L1 Cache. There is a 512K Error Correcting internal L2 cache apparently operating at half CPU speed. Power is 25.3 watts at 450MHz.

[Note that the above is based on Intel's descriptions of the CPU. Other sources have it at 1.8 volts and with a full CPU speed L2].

Features include:

70 new multimedia instructions. As with MMX, these are used only by new software designed to use them.
CPU ID. This feature may have been disabled at the last minute as a result of customer protests. (Intel's web page says the CPU ID can be enabled by the user. C't Magazine says it can probably be enabled remotely)
Designed to use a 100MHz Bus at 4.5, 5x, multipliers.
A Xeon PIII is mentioned, but no details are available.

Benchmarks on the 450MHz CPU show little difference from a Pentium II at the same clock speed. Specint95 runs at 18.7 vs 18.5 for the PII. Sysmark98 on NT4.0 is identical at 204. Business Winstone is identical at 23.3. iComp 3 rating is 1450 vs 1240 for the Pentium II

A patch is apparently required with Windows NT and Windows 98 to work with Katmai New Instructions (KNI) also known as Streaming SIMD Extensions (SSE).

Most, not all, Pentium II motherboards can use a Pentium III without modification. A few will be unable to deliver enough power to support the PIII.