We were seeing the same problems, slow network issues. This has been sucessful for us on new HP servers with NC373i nics. We didn't have to buy Intel cards.
An update to turn off default SNP features is available for Windows Server 2003-based and Small Business Server 2003-based computers (KB 948496)
There is a *new* High-priority/Non-Security update for Windows Server 2003 Post-SP2 which was recently released, and you should consider installing this update on any Windows Server 2003-SP2 Server. This hotfix disables the new Scalable Networking Pack, SNP, features that were delivered with Windows Server 2003 SP2. These SNP features were designed to offload a lot of the overhead processing required for network operations from the Operating system to compatible network adapter hardware.
For more background information on the SNP, you can read about these features here:
http://technet.microsoft.com/en-us/library/bb878074.aspx Within our Support organization, we have received a number of calls from Customers that were having network related issues and turning off these features, which are enabled by default with Windows Server 2003 SP2, solved the problem. It appears that there have been some incompatibilities with these advanced features and some of the older drivers for these cards which support these features.
Our recommendation is that unless you have specific requirements for enabling these advanced networking features, Customers install this hotfix to disable the SNP.
Please note that this applies to only Windows Server 2003 SP2 Servers, where this feature was enabled by default.
To review and obtain this hotfix, please follow this link:
http://support.microsoft.com/?id=948496
