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The R8000 which was introduced in 1994 was the first superscalar MIPS design, able to execute two ALU and two memory operations per cycle. The design was spread over six chips: an integer unit (with 16KB instruction and 16KB L1 data caches), a floating-point unit, three full-custom secondary cache tag RAMs (two for secondary cache accesses, one for bus snooping), and a cache controller ASIC. The design had two fully pipelined double precision multiply-add units, which could stream data from the 4MB off-chip secondary cache. The R8000 powered SGI's Power Challenge computer servers in the mid 1990s and later became available in the Indigo2 Power workstation. Its limited integer performance and high cost dampened appeal for most users, although its FPU performance fit scientific users quite well, and the R8000 was in the marketplace for only a year and remains fairly rare.


H1 or as it's codename was Beast was another highperformance MIPS V microprocessor. Little was known about beast except it being designed by the same people that made the R8000. Supposedly being a 12-issue processor would have made it's design an extremly ambitious project, probably again with a massive imballance between integer and floating point performance. Announced on May 12-1997 it's end along with it's successor H2 codenamed Capitan was already announced on August 4 of the same year. Capitan which was aiming at increasing memory bandwidth and scalability. It's believed that axing these two projects was a good idea because of the extreme complexity of designing a new microprocessor from scratch. The R10000 successors did demonstrate that an evolutionary approach indeed can work well.


In the spinout from SGI in 1997 MIPS Technologies inheritied the rights to the R8000 and eventually gave permission to distribute the R8000 documentation below.

Documentation license

Copyright (c) 2004 MIPS Technologies, Inc.
All rights reserved.

Unpublished rights (if any) reserved under the copyright laws of the United States of America and other countries. The contents of this document may not be copied or duplicated in any form, in whole or in part, without the prior written permission of MIPS Technologies, Inc. ("MIPS Technologies").

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The information contained in this document shall not be exported, reexported, transferred, or released, directly or indirectly, in violation of the law of any country or international law, regulation, treaty, Executive Order, statute, amendments or supplements thereto. Should a conflict arise regarding the export, reexport, transfer, or release of the information contained in this document, the laws of the United States of America shall be the governing law.

The information contained in this document constitutes one or more of the following: commercial computer software, commercial computer software documentation or other commercial items. If the user of this information, or any related documentation of any kind, including related technical data or manuals, is an agency, department, or other entity of the United States government ("Government"), the use, duplication, reproduction, release, modification, disclosure, or transfer of this information, or any related documentation of any kind, is restricted in accordance with Federal Acquisition Regulation 12.212 for civilian agencies and Defense Federal Acquisition Regulation Supplement 227.7202 for military agencies. The use of this information by the Government is further restricted in accordance with the terms of the license agreement(s) and/or applicable contract terms and conditions covering this information from MIPS Technologies.

Documentation files

  • http://www.linux-mips.org/pub/mips/docs/r8000/r8000-um.pdf
    At this time unfortunately only paper compies of the R8000 manuals are available, so the electronic documents available here are PDFs created from 300dpi scans. We'll continue trying to obtain electronic copies of these documents and make them available on this page. This is a 15MB PDF file primarily intended for printing. It will display very slowly in all but the fastest pdf readers.
  • http://www.linux-mips.org/pub/mips/docs/r8000/r8000-um.tar.bz2
    This 35MB tarball contains the unprocessed 300dpi bw and greyscale scans. Mostly here in case a bold soul wants to try to ocr the documents.