Editing Sequent Computer Systems (section)

===Symmetry===
Their next series was the [[Intel 80386]]-based Symmetry, released in 1987. Various models supported between 2 and 30 processors, using a new [[write-back cache|copy-back cache]] and a wider [[64-bit]] [[Front side bus|memory bus]]. 1991's Symmetry 2000 models added multiple [[SCSI]] boards, and were offered in versions with from one to six [[Intel 80486]] processors. The next year they added the [[VMEbus]] based Symmetry 2000/x50 with faster CPUs.

[[File:Sequent S81.jpg|thumb|right|Sequent S81 system]]
The late 1980s and early 1990s saw big changes on the software side for Sequent. DYNIX was replaced by DYNIX/ptx, which was based on a merger of [[AT&T Corporation]]'s [[UNIX System V]] and [[Berkeley Software Distribution|4.2BSD]]. And this was during a period when Sequent's high-end systems became particularly successful due to a close working relationship with [[Oracle Corporation|Oracle]], specifically [[Oracle database|their high-end database servers]]. In 1993 they added the Symmetry 2000/x90 along with their ptx/Cluster software, which added various [[High-availability cluster|high availability]] features and introduced custom support for [[Oracle Parallel Server]].

In 1994 Sequent introduced the Symmetry 5000 series models SE20, SE60 and SE90, which used 66&nbsp;MHz [[Pentium (original)|Pentium]] CPUs in systems from 2 to 30 processors.<ref name=RICM/> The next year they expanded that with the SE30/70/100 lineup using 100&nbsp;MHz Pentiums,<ref name=RICM/> and then in 1996 with the SE40/80/120 with 166&nbsp;MHz Pentiums. A variant of the Symmetry 5000, the WinServer 5000 series, ran [[Windows NT]] instead of DYNIX/ptx.<ref name="winserver">{{cite web|url=http://www.allbusiness.com/technology/software-services-applications-computer/7126055-1.html|title=Sequent Unveils New High-End Systems for Windows NT; Based on Industry-Leading Platform Symmetry Platform|date=1995-05-23|work=[[Business Wire]]|accessdate=2009-03-23}}</ref>