Tests by IT Week Labs indicate that the latest version of the open-source Samba file and print server software has widened the performance gap separating it from the commercial Windows alternative.

Samba is an open-source implementation of the Common Internet File System (CIFS) protocol used for file and print sharing by PCs running Microsoft Windows. Samba 3, released last month, is a long-awaited upgrade that adds important new features, most notably compatibility with Microsoft Active Directory. Version 3 can be set up to authenticate users from an existing Active Directory.

The latest benchmark results show an improvement over version 2, which performed twice as fast as Windows 2000 Server when it was tested by IT Week Labs last year. Overall, it now performs 2.5 times faster than Windows Server 2003.

In terms of scalability, the gains of upgrading to Samba 3 are even more striking. Last year we found that Samba could handle four times as many clients as Windows 2000 before performance began to drop off. This year we would need to upgrade our test network in order to identify the point where Samba performance begins to fall in earnest.

IT managers say Samba's better performance means they can use cheaper servers than would be possible with Windows software. And if they run Samba in a completely open-source environment, such as on Linux, they could remove the cost of Windows server licences. Samba is available free of charge for commercial Unix versions including IBM AIX, HP-UX and Solaris. It is also available for various versions of Linux, Novell NetWare and VMS.

The IT Week Labs tests used Ziff-Davis NetBench file server benchmark with 48 client systems. We selected a low-specification but otherwise modern server for our tests. We used an HP ProLiant BL10 eClass Server fitted with a 900MHz Pentium III chip, a single 40GB ATA hard disk and 512MB of RAM. We did not tune any of the software to improve performance.

Each NetBench client makes a constant stream of file requests to the server under test, whereas in real-world environments many users would remain idle for long periods. Consequently our test environment simulates the workload of some 500 client PCs in a typical production environment.