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150MHz R4400 CPU Upgrade

[A picture of the 150MHz R4400 CPU module] Features


(*) Estimated
The IRIS Indigo 150 MHz R4400 CPU upgrade brings the latest MIPS RISC technology to IRIS Indigo and Indigo2 system users. The R4400 processor implements several major design improvements to the MIPS R4000 CPU that result in significantly enhanced application performance. The R4400 CPU's 150 MHz internal clock speed is 50 percent faster than the R4000 CPU. In addition, the R4400 processor doubles the size of the R4000's on-chip caches; its 16 KB data and instruction caches are among the largest on-chip caches available today. The on-chip caches combine with 1 MB of secondary cache to give the IRIS Indigo family the highest performing cache architecture available on the desktop. The R4400 CPU also implements a new on-chip buffer that allows the CPU to continue running when a write to an uncached memory address occurs. These enhancements result in typical application performance improvements of approximately 40 percent when compared to 50 MHz R4000-based IRIS Indigo systems.

The R4400 CPU offers IRIS Indigo and Indigo2 system users an extremely well balanced compute engine for applications doing both integer and floating-point computation. When combined with Silicon Graphics' high performance system architecture, an R4400 upgraded Indigo system gives users industry leading application performance.

[R4400 CPU/System Diagram] Clock Frequency

Cache Memory

Primary (on-chip)


CPU Memory

Input/Output Ports

High Performance CPU Coupled with a High Performance System Architecture.

Silicon Graphics has always designed computer systems as exactly that: systems. A high performance microprocessor like the MIPS R4400 is underutilized if the surrounding system architecture is not optimized to take advantage of its compute power. IRIS Indigo systems are designed to get the most out of the R4400 CPU. IRIS Indigo systems based on the R4000 family of microprocessors implement a 64-bit CPU bus as well as Silicon Graphics high performance GIO system bus.

IRIS Indigo systems implement four Silicon Graphics designed ASICS to help optimize system performance. Two of these ASICS control the system's very high memory bandwidth (up to 400 MB/sec). This memory bandwidth coupled with one megabyte of secondary cache ensures efficient memory transactions. The remaining two ASICS control the peripheral and graphics interfaces.

The combination of the 150 MHz MIPS R4400 and Silicon Graphics high performance system architecture results in a system capable of supporting the most demanding applications.

Typed up by Ian Mapleson (mapleson@gamers.org)
Original Document Code: IND-FAM-DS (01/93)
Last Change: 13/Jun/98

Ian's SGI Depot: FOR SALE! SGI Systems, Parts, Spares and Upgrades

(check my current auctions!)
[WhatsNew] [P.I.] [Indigo] [Indy] [O2] [Indigo2] [Crimson] [Challenge] [Onyx] [Octane] [Origin] [Onyx2]
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