Indy, a Silicon Graphics Indy

The Indy was the low end workstation with Indigo2 being its bigger borther. It was, like the Indigo2, originally equipped with R4000 series (MIPS III) CPU:s, but was eventually available with R5000 series (MIPS IV) CPU:s. (The Indigo2 took the R8000, R10000 route to MIPS IV which the Indy never did).

Indy:s were available with both so called "SC" and "PC" CPU:s. "SC" indicates that the CPU has 2nd level cache while "PC" lacks this ability and thus is restricted to 1st level cache only. There was also a version called "MP" which was an "SC" with multiprocessor support but this was ofcourse never used in the Indy as it is a single processor design. The R4400SC has a separate interface to the 2nd level cache with a higher bandwidth than its RAM memory interface.

Compared to the DECstations it shall be noted that SGI:s run their CPU:s in big endian mode while DEC configured there machines for little endianness (as this is the tradition from VAX). This means that binaries are not interchangable between DECstations and SGI:s even if the same operating system may be loaded on them (e.g. NetBSD).