The Advanced Computing Environment was defined by an industry consortium in the early 1990s to be the next generation commodity computing platform, the successor to personal computers based on Intel's 32-bit instruction set architecture. The effort found little support in the market and dissolved due to a lack of sales and infighting within the group.
Soon after the initiative was announced, a dissenting faction of seven ACE members declared that the decision to support only little-endian architectures was short-sighted. This subgroup, known as the Apache Group, promoted a big-endian alternative. The group, whose name was conceived as a pun on "Big Indian", was unrelated to the later Apache Software Foundation. It later adopted the name MIPS/Open. A rift within the ACE consortium was averted when it was decided to add support for big-endian SVR4.
Dissolution
Even so, the ACE initiative began to fall apart little more than a year after it started, as it became apparent that there was not a mass market for an alternative to the Wintel computing platform. The upstart platforms did not offer enough performance improvement from the incumbent PC and there were major cost disadvantages of such systems due to the low volume production. When the initiative started, RISC based systems had substantial performance advantage over Intel 80486 and original Pentium chips. Intel quickly migrated the Pentium design to newer semiconductor process generations and that performance advantage slipped away. Compaq was the first company to leave the consortium, stating that with the departure of CEO Rod Canion, one of the primary backers behind the formation of ACE, they were shifting priorities away from higher-end systems. This was followed in short order by SCO announcing that they were suspending all work on moving their version of Unix to the MIPS platform. There were other potential conflicts: earlier that year, MIPS had been purchased by SGI, which may have also contributed to concerns about the neutrality of the target platform. DEC had released their Alpha processor and were less interested in promoting a competing architecture. And finally, the significant improvements in Intel x86 performance made abandoning it less attractive, and although ACE supported x86 for a time, Intel was never a member.
ARC
The main product of the ACE group is the Advanced RISC Computing specification, or ARC. It was initially based on MIPS-basedcomputer hardware and firmware environment. Although ACE went defunct, and no computer was ever manufactured which fully complied with the ARC standard, the ARC system still exerts a widespread legacy in that all Microsoft Windows NT-based operating systems used ARC conventions for naming boot devices before Windows Vista. Further, SGI used a modified version of the ARC firmware in its systems. All SGI computers which run IRIX 6.1 or later boot from an ARCS console. In addition, most of the various RISC-based computers designed to run Windows NT used versions of the ARC boot console to boot NT. Among these computers were:
MIPS R4000-based systems such as the MIPS Magnum workstation
all Alpha-based machines with a PCI bus designed prior to the end of support for Windows NT Alpha in September 1999
It was also predicted that Intel IA-32-based computers would adopt the ARC console, although only SGI ever marketed such IA-32-based machines with ARC firmware.
