PA-7100
First PA-RISC microprocessor with on-die floating-point unit.
The PA-7100, also called the PCX-T and code-named Thunderbird, was a microprocessor from Hewlett-Packard (HP) that used the PA-RISC 1.1 instruction set architecture. Launched in early 1992, it was the first PA-RISC chip to include the floating-point unit directly on the same die. Its main rival in the workstation and server space was Digital Equipment Corporation’s Alpha 21064. HP used the PA-7100 in its HP 9000 workstations, and Stratus Computer employed it in Continuum fault-tolerant servers. Samsung also released HP-UX workstations based on the PA-7100, using system technology licensed from HP.
This chip evolved from the PA-7000 (PCX-S) chip set, an earlier PA-RISC design that used separate microprocessor and FPU chips. HP built the PA-7100 using its CMOS26B process, a complementary metal–oxide–semiconductor (CMOS) fabrication method, and packaged it in a 504-pin ceramic pin grid array with a copper-tungsten heat spreader. Manufacturing took place at HP’s plants in Corvallis, Oregon, and Fort Collins, Colorado.
An upgraded version, the PA-7150, arrived in 1994. It ran at a higher clock speed thanks to improved circuit design, but still used the same CMOS26B process. Both the PA-7100LC and PA-7200 microprocessors were also derived from the PA-7100.
- Introduced
- early 1992
- Isa
- PA-RISC 1.1
- Code name
- Thunderbird (PCX-T)
- Fpu
- Integrated on-die (first PA-RISC to do so)
- Package
- 504-pin ceramic pin grid array with copper-tungsten heat spreader
- Fabrication process
- HP CMOS26B (complementary metal–oxide–semiconductor)
- Fabrication plants
- HP's Corvallis, Oregon and Fort Collins, Colorado
Lore & Background
The PA-7100 was based on the PA-7000 (PCX-S) chip set, a previous PA-RISC implementation consisting of a microprocessor and FPU. It was fabricated by HP in their CMOS26B process. Users of the PA-7100 included HP in its HP 9000 workstations and Stratus Computer in its Continuum fault-tolerant servers. Samsung also introduced workstations running HP-UX based on the PA-7100 and system technology licensed from HP.
An improved version, the PA-7150, was introduced in 1994 and operated at a higher clock speed due to improved circuit design, fabricated in the same CMOS26B process. Both microprocessors were fabricated at HP's Corvallis, Oregon and Fort Collins, Colorado fabrication plants. The PA-7100LC and PA-7200 microprocessors were also based on the PA-7100.
Reader's Guide
The PA-7100 marked a significant step in HP's PA-RISC line by integrating the floating-point unit on the same die, a first for the architecture. This integration simplified system design and improved performance for floating-point-intensive workloads. Its primary competitor was the DEC Alpha 21064, placing it in the high-end workstation and server segments. HP used the PA-7100 in its HP 9000 workstations, while Stratus Computer employed it in Continuum fault-tolerant servers, indicating its reliability for mission-critical applications. Samsung's licensing of HP system technology to produce HP-UX workstations shows the PA-7100's influence extended beyond HP's own products. The later PA-7150, a speed-bumped version, and the derivative PA-7100LC and PA-7200 microprocessors demonstrate the PA-7100's role as a foundational design for subsequent PA-RISC generations. Its fabrication in HP's CMOS26B process at two plants underscores the manufacturing scale and investment behind the chip.
Did You Know?
- The PA-7100 is also known as the PCX-T and by its code name Thunderbird.
- It was the first PA-RISC microprocessor to integrate the floating-point unit on-die.
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