Unix server operating system sales will exceed expectations in the next 12 months, according to researcher IDC. Vernon Turner, an analyst at the company, said: "It looks like there will be more Unix sold this year than ever before."

Chris Ingle, research associate for systems and servers at IDC, said that this pricing model is the way the market is moving. "Systems are either shipping with more processors that can be turned on, or firms will start shipping additional boxes that can be paid for as and when you use them," he said.

Turner claimed that other server market trends include increasing demand for bandwidth, storage capacity and processing power.

Vendors are also looking at the impact of Linux at the low end of the Unix server market and are reacting differently to the threat it poses. Carly Fiorina, chief executive at Hewlett Packard (HP), said that Superdome would be able to run Linux- and Windows NT-based applications alongside Unix ones, while IBM has thrown its weight behind the open source operating system in an attempt to clean up on the services front.

Sun Microsystems, on the other hand, has given Linux a cool reception and has continued to push Solaris, its own version of Unix. It has also denied rumours that it acquired Cobalt for its Linux expertise.

Turner said that IBM, Sun, HP, Dell and Compaq share about 65 per cent of the server market between them, and that as they continued to grow, the smaller fish would get smaller. But it remains to be seen which, if any, has come up with a winning strategy that will leave the others behind.