Microsoft formally rolled out its long-delayed Windows 2000 operating system late yesterday evening – and reliability and stability figured highly in the presentation. Appearing before an enthusiastic crowd, Bill Gates made his first major appearance in his new role as Microsoft chairman and chief software architect. A relaxed Gates was joined on stage by actor Patrick Stewart, best known for his role in Star Trek: The Next Generation. The launch event was dominated by a long series of demonstrations designed to show off the operating system's features for mobile workers, systems administrators and enterprise data centers. Many of the demonstrations were met with loud cheers from the audience, an unusual occurrence at Microsoft's generally tightly scripted but relatively emotionless launch events. Despite the product's multiple delays and lengthy beta cycle, Gates still managed to come up with some surprises. Chief among them: some benchmark numbers audited yesterday that clock Windows 2000 Advanced Server running SQL Server 2000 on a 12-node Compaq ProLiant cluster at 227,079 TPM-C (transactions per minute). Those numbers comfortably beat the previous top performers, consisting of servers from IBM and Sun Microsystems Inc. that all hit around 150,000 TPM-C. Gates said Windows 2000 could attain these numbers at one-third of the cost per transaction of a Unix-based system. The cluster used for the benchmark would sell for $2.9 million (around £1.8m), Gates said. In a demonstration of Windows 2000's scalability, 400 Dell Computer Corp. workstations were shown generating the equivalent of 1.6 billion hits per day against 32 clustered servers running the CBS MarketWatch Web site. The audience was shown how servers could be added to the cluster without need for any manual software configuration. The load automatically spread over the new servers. Gates said 20,000 "dot-com" sites are already running on Windows 2000, and boast uptimes of more than 99.95 per cent. The crowd was also shown a 16-way Unisys ES7000 server running Windows 2000 Datacenter Edition. An application running on eight processors was, with a click of the mouse, spread out over an additional four processors using a piece of code called the Job Object Manager.