Available models

Available models

Pentium Pro clock speeds were 150, 166, 180 or 200 MHz with a 60 or 66 MHz external bus clock. Some users chose to overclock their Pentium Pro chips, with the 200 MHz version often being run at 233 MHz, and the 150 MHz version often being run at 166 MHz. The chip was popular in symmetric multiprocessing configurations, with dual and quad SMP server and workstation setups being commonplace.

In Intel's "Family/Model/Stepping" scheme, the Pentium Pro is family 6, model 1, and its Intel Product code is 80521.

Evolution in fabrication

As time progressed, the process used to fabricate the Pentium Pro processor die and its separate cache memory die changed, leading to a combination of processes used in the same package:

* The 133 Mhz Pentium Pro processor die, the prototype of the 150 mhz , was fabricated in a BiCMOS process (only a very few samples survive).
* The 150 MHz Pentium Pro processor die was fabricated in a 0.50 μm BiCMOS process.
* The 166, 180, and 200 MHz Pentium Pro processor die was fabricated in a 0.35 μm BiCMOS process.
* The 256 KB L2 cache die was fabricated in a 0.50 μm BiCMOS process.
* The 512 and 1024 KB L2 cache die was fabricated in a 0.35 μm BiCMOS process.

Upgrade paths

In 1998, the 300/333 MHz Pentium II Overdrive processor for Socket 8 was released. Featuring 512 KB of full-speed cache, it was produced by Intel as a drop-in upgrade option for owners of Pentium Pro systems (the BIOS of the motherboard sometimes had to be updated). However, it was officially supported by Intel only in single or dual-processor mode, not 4-way or higher, which did not make it a usable upgrade for high end quad-processor systems.

As Slot 1 motherboards became prevalent, several manufacturers released slockets, such as the Tyan M2020, Asus C-P6S1, Tekram P6SL1 and the Abit KP6, to allow Pentium Pro processors to be used in them. The Intel 440FX chipset explicitly supports both Pentium Pro and Pentium II processors so using a slocket with them is straightforward. However, since the Intel 440BX and later Slot 1 chipsets do not explicitly support the Pentium Pro, the only Socket 8 processor that will usually work with a slocket in such a motherboard is the Pentium II Overdrive, since it is in essence a Pentium II processor.