Soi; On-Chip Copper-Wiring Technology; Hot-Plugging - IBM i series Handbook

iSeries Architecture: Fundamental Strength of the iSeries
away. The iSeries models are uniquely positioned to exploit this characteristic of object
persistence, where customary systems use a less-elegant mechanism that requires them to
store their persistent objects in a separate file system, with all the attendant performance
implications.

SOI

The Silicon on Insulator (SOI) technology was applied for the first time for the iSeries with
OS/400 V4R5. This technology is used by the iStar processors of the iSeries. The transistors
are built within and on top of a thin layer of silicon that is on top of an insulating layer. The
insulating layer is fabricated by implanting a thin layer of oxide beneath the primary silicon
surface of the wafer.

On-chip Copper-wiring Technology

Pulsar, iStar, and SStar processors use on-chip copper-wiring technology. Pulsar processors
integrate IBM CMOS7S technology. iStar and SStar processors integrate IBM CMOS8S
technology. Northstar technology used in prior AS/400e processors deploys aluminum for
on-chip wiring.
Copper's better conductivity permits thinner wires to be used, which enables the transistors
to be packed closer together. This new denser technology permits additional micro
architecture methods to improve performance. Denser processor technology also permits
more on-chip cache. Keeping multiple levels of high speed cache is enables efficient
utilization of the processors.

Hot-plugging

The term "hot-plug PCI" is used by the computing industry for a wide range of purposes.
Primarily, hot-plug PCI refers to the technology that allows users to install and remove PCI
devices while the computer is running. For iSeries servers, "hot-plug" is known as concurrent
maintenance.
A method must be in place to inform the operating system of insertion and removal events.
Driven by the demand for the highest possible availability, PCI hot-plugging is available
beginning with OS/400 V4R5 on all iSeries 8xx models and some of the 270 models. A brief
description of how hot-plugging is implemented on the iSeries follows.
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iSeries Handbook