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Poor network performance on Windows 2008 Server virtual machine (1009517)

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A virtual machine running a Windows 2008 Server may experience these symptoms:
  • Poor network performance
  • Slow network transfers


To resolve this issue, ensure that the virtual machine uses an Intel e1000 driver or enhanced vmxnet or vmxnet3 driver (depending on the ESXi/ESX version support) for the virtual network card. Also, ensure to disable TCP segmentation Offload (TSO).

To disable TSO:

Note: This procedure modifies the Windows registry. Before making any registry modifications, ensure that you have a current and valid backup of the registry and the virtual machine. For more information on backing up and restoring the registry, see the Microsoft Knowledge Base article 136393.

The preceding link was correct as of November 27, 2013. If you find the link is broken, provide feedback and a VMware employee will update the link.
  1. Click Start > Run, type regedit, and click OK. The Registry Editor Window opens.
  2. Navigate to the HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ registry key.
  3. If the key does not exist select Edit > New > DWORD (32-bit Value).
  4. Type DisableTaskOffload for the name of the key and press Enter to save the changes.
  5. Right-click the DisableTaskOffload key and click Modify.
  6. Change the value data to 1.
  7. Click OK to accept the changes.

To disable TCP Segmentation Offloading in Windows 2008:

  1. Run this command:

    netsh int tcp set global chimney=disabled

  2. Reboot the virtual machine.
Note: The provided registry value only changes one of many parameters, while the above command updates all the necessary parameters.

Additional Information

For more information about:
Note: The preceding links were correct as of November 21, 2013. If you find a link is broken, provide feedback and a VMware employee will update the link.



See Also

Update History

08/04/2010 - We have 15 link counts to the article, and the content is not confidential hence making this article public. 05/03/2011 - Added ESX 4.0 and 4.1 to Product Versions. 02/03/2012 - Added ESXi and vCenter Server 5.0 to Product Versions. 11/21/2013 - Added ESXi and vCenter Server 5.1/5.5 to Product Versions. 01/10/2014 - Added steps to create Key if not available. Changed registry path per feedback.

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  • 102 Ratings