Offload TCP processing to the network controllers under Vista, Server 2008, and Windows 7

After upgrading my home PC to Windows 7, I was decided to see if my motherboard/CPU combination support hardware virtualization.  You need hardware virtualization support if you want to run Windows XP Mode or Windows Virtual PC.  I have an XMD Athlon X2 with an Asus M2N-SLI Deluxe and I’m not sure if that combination supports hardware virtualization.  I’m pretty sure the CPU does, but I don’t yet yet know about the motherboard.

I decided to check the  Asus support forum to see that motherboard supports hardware virtualization and while reading through the forum, I found an a post about tweaking the network settings for a boost in performance.  The TCP/IP stack in Vista has the ability to offload some of the network processing to the network controller, if the network controller has that capability.  Out of the box, Vista disables that feature to prevent problems with controllers that don’t support that feature.

From what was posted in the Asus forum, this motherboard does support that feature.  This motherboard is based on the NVIDIA nForce 570 chipset, which included dual Gigabit LAN controllers.  If you are doing CPU intensive tasks, you can gain some performance benefit by offloading the TCP processing to the network controllers.

Vista refers to this setting as the “Chimney Offload State”.  It’s easy to check and set this value.  if you have a newish motherboard with a Gigabit speed network controller, this should work for you.

To change this setting, do the following:

1. Open an elevated command prompt.  Either right-click cmd.exe and select “Run as Administrator” or press the Start button, type “cmd” and then hold the left shift and left control keys while pressing the enter key.
2. Check the current status of the Chimney Offload state by running the following command:
   netsh int tcp show global
   The possible values for that state are: disabled, enabled, default
3. Run the following command to enable Chimney Offload state
   netsh int tcp set global chimney=enable

Before making the changes, check your current broadband speed.  I like the one at speedtest.net, but the others are fine.  Then after making the change, check it again.  If the performance takes a hit, set the state back to it’s original value.  Not only did it work for me, I did get a slight, but measurable, download speed increase.

Before enabling Chimney Offload:

After:

These tests were run a few times before and after the modification.  I picked the average score each time.  That helps even out any existing network traffic that would affect the results.  Going from 17.42 MB/s to 18.70 wasn’t a huge increase, about 7%; but I’ll take it.  There are other settings that you can tweak.  Some are mentioned in the forum posting, and they are also documented in an article in speedguide.net as well.  You don’t often get a free lunch, this is a good one to take.  This setting works for Vista, Server 2008, and Windows 7.  I still don’t know if I can get hardware virtualization, but this was an interesting diversion.

[edited on 8/24/09]
As it turns out, my CPU and motherboard do support hardware virtualization, it just took a little work.

Know your SQL Server version

There are times where you need to know what version of SQL Server is installed.  Usually you want to know which version and which service pack has been applied.  There have been a few isolated cases over the years where we saw bugs go away or significant performance boosts by merely installing the latest service pack.  It's less of an issue with 2005, but with SQL Server 2000, we wanted to make sure the user installed the latest service packs to block against stuff like the "Slammer" worm.

The following bit of T-SQL will send back the version information in easy to process pieces

SELECT SERVERPROPERTY('productversion') AS ProductVersion, SERVERPROPERTY ('productlevel') AS ProductLevel, SERVERPROPERTY ('edition') AS Edition

For SQL Server 2005, you could get back something like this:

ProductVersion  ProductLevel  Edition
--------------- ------------- ----------------
9.00.2047.00    SP1           Standard Edition

Which indicates the Standard Edition of SQL Server 2005, with Service Pack 1 installed.  You can also get most of that information with

select @@version

But you would have to parse out the version from a block of text like this:

----------------------------------------------------------------------
Microsoft SQL Server 2005 - 9.00.2047.00 (Intel X86) 
 Apr 14 2006 01:12:25 
 Copyright (c) 1988-2005 Microsoft Corporation
 Standard Edition on Windows NT 5.2 (Build 3790: Service Pack 2)

Using SERVERPROPERTY (2000, 2005 or 2008) is much easier than parsing that block of text.  To determine which version is running based just on the version number, Microsoft has a KB article that lists all of the releases under KB321185.

VMware-authd.exe slowing down my PC

I was doing some work on one of my PC's and I had the processes list open in Task Manager. Out of the corner of my eye, I noticed that one process, VMware-authd.exe, was going from 0 to 10% of the CPU. I didn't know what that process did, I went out on a limb and assumed that it was somehow related to VMWare. VMware is one of my favorite tools, but I wasn't running any VMWare sessions. Time to go Googling. Apparently it's a service that provides administrator priviledges to to a running VMWare session if the host use isn't logged in with administrator access rights

If you are logged in with admin rights, you don't need to have this service running. VMware-authd.exe is the name of the executable for the "VMware Authorization Service" service. You can go into Services and shut that service down and then set it's startup type to "manual". There are no other services that depend on that service to be running. You can also stop the service from the Windows command line with the following:

net stop VMAuthdService

[Edited on 3/5/08]

If you need to restart the service from the command line, use the following:

net start VMAuthdService