Skip to main content
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Enjoy members-only rewards and discounts
  • Create and access a list of your products

Windows Server: Disabling TCP Chimney Offloading and Autotuning May Improve iSCSI Performance

Summary: Disable TCP chimney offloading and receive window autotuning in Windows Server to improve iSCSI performance.

This article applies to   This article does not apply to 

Symptoms

How to disable TCP chimney offloading and receive window autotuning in Windows Server, which may improve iSCSI network performance

TCP chimney offloading and receive window auto-tuning are frequently disabled as part of the process of troubleshooting a network-related issue on a Windows server. In some cases, disabling these can improve network performance in general and/or iSCSI performance specifically.
 

Note: Performing the procedure in this article is not guaranteed to improve network performance, and there is a chance that it will have the opposite effect. It is recommended that the procedure in this article be performed during a scheduled maintenance window and that performance testing be conducted before the server is returned to production.
  1. Run the following command from an elevated command prompt to disable TCP chimney offloading: 
    • Netsh int tcp set global chimney=disabled
  2. Disable TCP receive window auto-tuning by running the following command:
    • Netsh int tcp set global autotuning=disabled
 

  

Affected Products

Servers, PowerEdge