From KVM
Line 1: Line 1:
'''Windows registry settings'''
 
 
 
This page describes best practice for configuring Windows TCP\IP related parameters to archive the best performance with Windows guests.
 
This page describes best practice for configuring Windows TCP\IP related parameters to archive the best performance with Windows guests.
 
Those parameters are unrelated to kvm\VirtIO drivers , rather general Windows settings.
 
Those parameters are unrelated to kvm\VirtIO drivers , rather general Windows settings.
 
After changing those setting reboot is required for the changes to effect the system.
 
After changing those setting reboot is required for the changes to effect the system.
  
= Registry settings =
+
= Windows XP and 2003 registry settings =
 +
 
 +
== Registry settings ==
  
 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters]
 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters]
Line 27: Line 27:
 
* "FastSendDatagramThreshold" - controls fast UDP transmit.  
 
* "FastSendDatagramThreshold" - controls fast UDP transmit.  
  
= Additional links =
+
== Additional links ==
 
* [http://technet.microsoft.com/en-us/library/cc781532(WS.10).aspx Windows Sockets and DNS Registry Parameters]
 
* [http://technet.microsoft.com/en-us/library/cc781532(WS.10).aspx Windows Sockets and DNS Registry Parameters]
 
* [http://support.microsoft.com/kb/235257 Server Does Not Use All Bandwidth Available When Streaming Files with Bit Rates over 100 Kbps]
 
* [http://support.microsoft.com/kb/235257 Server Does Not Use All Bandwidth Available When Streaming Files with Bit Rates over 100 Kbps]
 +
 +
 +
= Starting from Vista =

Revision as of 17:56, 15 January 2011

This page describes best practice for configuring Windows TCP\IP related parameters to archive the best performance with Windows guests. Those parameters are unrelated to kvm\VirtIO drivers , rather general Windows settings. After changing those setting reboot is required for the changes to effect the system.

Windows XP and 2003 registry settings

Registry settings

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters]

"DefaultSendWindow"=dword:00100000

"DefaultReceiveWindow"=dword:00100000

"FastSendDatagramThreshold"=dword:00004000


[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]

"Tcp1323Opts"=dword:00000001

"TcpWindowSize"=dword:00100000


  • Tcp1323Opts - allows the scaling of the TCP window above 16k. For more info read Tcp1323Opts
  • "DefaultSendWindow", "DefaultReceiveWindow" and "TcpWindowSize" control TCP window size
  • "FastSendDatagramThreshold" - controls fast UDP transmit.

Additional links


Starting from Vista