“Microsoft recently launched a ‘Get the Facts’ ad campaign telling consumers Linux isn’t cheaper than Windows. The Advertising Standards Authority (ASA) thinks they should get the facts too - but it’s warned Microsoft to make sure its are straight first.

A print ad from Microsoft which bore the headline “Weighing the cost of Linux vs.Windows? Let’s review the facts” offered a comparison between a Windows and a Linux machine which, according to Redmond, demonstrated that “Linux was found to be over 10 times more expensive than Windows Server… for Windows-comparable functions of file serving and Web serving. The results showed that IBM z900 mainframe running Linux is much less capable and vastly more expensive than Windows Server 2003 as a platform for server consolidation.”

Microsoft claimed the study was as like-for-like as it could be between the machines - a Linux image on IBM’s z900 mainframe CPUs and a Windows Server 2003 image running on two 900MHz Xeon CPUs - and wasn’t hardware specific.

The ASA, however, thought the choice of hardware could have been more appropriate, saying in its adjudication: “The Authority understood… that the measurements for Linux were performed on an IBM zSeries, which was more expensive and did not perform as well as other IBM Series.”