IDC found that Linux cost less than Windows for hosting Web sites, but that in four other areas Windows 2000 was less expensive overall. "The cost advantages are driven primarily by Windows' significantly lower costs for IT (information technology) staffing, generally the largest single component of IT costs," IDC said in the study.
The Microsoft-funded study, released Monday, polled 104 North American companies and evaluated costs for networked server computers supporting 100 users over a five-year period. The servers were used for tasks ranging from sharing files, running protective firewall software, and sending print jobs to printers--typically jobs run on lower-end servers where Linux and Windows are most widely used.
The biggest difference was in security servers, where Linux systems cost $91,000 over five years and Windows systems cost $70,000, IDC said. Next came print jobs, where a Linux server cost $107,000 over five years and a Windows server cost $87,000. In file sharing, Linux cost $114,000 to Windows' $99,000. In Web site jobs, Linux was less expensive at $31,000 to Windows' $32,000.
The findings reinforce a long-held argument by Microsoft that its systems don't cost as much to run as Linux does. These administration costs account for the vast majority of the overall ownership cost--62 percent, according to IDC--dwarfing differences in the initial software costs.
Linux, unlike Windows, is available for free from companies such as , which also sell versions with manuals, technical support and other features. But a low initial price tag is not the deciding factor, IDC said.
Linux's price has been influential, however. For one thing, it spurred Microsoft to sell a new"Web Server" edition of the next version of Windows, .Net Server 2003 due in April. For another thing, Linux has companies such as Sun Microsystems to sell Unix servers.
And Microsoft acknowledges its own prices have been an issue in cash-strapped countries such as.
Software acquisition costs are 4.6 percent of the overall server costs over five years, and hardware acquisition is 4.4 percent, IDC said. Much more significant is the cost of unexpected computer downtime, when companies have to spend time rebooting and reconfiguring systems and the people who need to use the servers are idle.
IDC expects the overall cost gap between Linux and Windows to shrink as Linux becomes more widespread, administrators grow more familiar with it, and management software supports it better.
"We believe these higher costs are...related to the relative immaturity of the management tools available today for Linux systems," IDC said. Administrators, too, will become more adept. "Over time, the gap in support costs between Linux and Windows will contract."
While major management software packages from BMC Software, Computer Associates International, Hewlett-Packard and IBM are extending to include Linux, that software isn't free, IDC added. And Windows is a moving target: Its management tools are getting better as Linux improves, IDC said.