Disabling Large Send Offload – Windows

In an earlier post, I described the Large Send Offload (LSO) feature of modern Ethernet adapters and why it can cause havoc with network performance.  And since this is enabled by default, you have to manually disable it.  For Windows, this can be done in the Ethernet adapter properties (which I prefer) or in the TCP/IP network stack.  I'll start with disabling LSO in the TCP/IP network stack since Microsoft uses some confusing terms that you'll want to be familiar with. Micosoft refers to LSO as "TCP Chimney Offload".  For Windows Server 2008 and later, it's described in MS Support Article 951037.  LSO was first supported in Windows Server 2003 …

Continue reading →