For sometime I have found that on certain SBS server there have been some network performance issues which do not specifically seem to originate from anywhere specific. When you look at the spec’s of the server there are not bottlenecks or obvious issues but it just doesn’t seem to perform as well as you would expect. We it would seem that the answer is out there in the for of an update from Microsoft. The issue relates specifically with services with Windows 2003 Service Pack 2 installed or the Windows 2003 Scalable Network Pack on a computer that has a TCP/IP Offload-enabled network adapter. There is a number of ways in which this particular issue manifests itself however the one that I am currently looking into is “You experience slow network performance” as there has now been a number of site, one more recently, where the server performance on the new network is worse than the old system. So for any of you that want to look into this further the KB article is as follows http://support.microsoft.com/kb/948496 and its noteworthy that this update has been released as a critical update which means it should find it’s way onto most servers updates automatically however it’s worth checking anyway.