Aussie legend Cameron McBride and good friend Tony Sanchez from Citrix sent a heads up to me recently on some performance related hotfixes. They are specific to proc and SP1. Nevertheless they are definitely worth applying for the best performance.

 

Issue 1: Performance is not as awesome as it could be on Westmere or Sandybridge chipsets

http://support.microsoft.com/kb/2517329

Symptoms:

  • You have a Windows Server 2008 R2-based computer that has a large amount of physical memory and that has Intel Westmere or Sandy Bridge processors.

    For example, you have a computer that has Intel Xeon 5600 series processors and that has 48 gigabytes (GB) physical memory.
  • You install the Hyper-V role on the computer.

In this scenario, the performance of the computer may decrease.

For example, the following performance issues may be encountered:

  • The CPU usage is high and the server responds slowly when you copy large files on the computer. For example, you copy a 10-GB file.
  • The disk I/O performance of the virtual machines (VMs) is slow.
  • Windows takes a long time to start.
Issue 2: Networking Performance is not as awesome as it could be under load and is lost in certain scenarios
http://support.microsoft.com/kb/2263829/en-us
You install the Hyper-V role on a computer that is running Windows Server 2008 R2 Service Pack 1 (SP1).
  • You run a virtual machine on the computer.
  • You use a network adapter on the virtual machine to access a network.
  • You establish many concurrent network connections. Or, there is heavy outgoing network traffic.
In this scenario, the network connection on the virtual machine may be lost. Additionally, the network adapter may be disabled.

Notes
  • You must restart the virtual machine to recover from this issue.
  • This issue can also occur on versions of Windows Server 2008 R2 that do not have SP1 installed. To resolve the issue, apply the hotfix that is described in one of the following Microsoft Knowledge Base articles:
    974909 (http://support.microsoft.com/kb/974909/ ) The network connection of a running Hyper-V virtual machine is lost under heavy outgoing network traffic on a Windows Server 2008 R2-based computer

    2264080 (http://support.microsoft.com/kb/2264080/ ) An update rollup package for the Hyper-V role in Windows Server 2008 R2: August 24, 2010
So theres hotfixes for both of these. Thanks Cam and Tony for the heads up on this!