Confirming No Way Around Autotuning in Windows 7
Hello, I have been searching for a way to optimize a Gbps connection that is a Google Fiber Beta test site (Stanford Calif). The problem is that the autotuning is not stable and goes fast/slow. On the same router, cabling a WHS2011 system works perfectly. After a lot of work, the final setting selected was "highlyrestricted" If anyone wants more references to this problem, here are some useful links... all this applies to Verizon Fios fiber and other fast systems when they arrive: http://www.speedguide.net/articles/windows-7-vista-2008-tweaks-2574 http://www.dslreports.com/forum/sharing http://www.msfn.org/board/topic/87969-heres-why-tcpwindowsize-does-not-work-in-vista/ http://technet.microsoft.com/en-us/magazine/2007.01.cableguy.aspx http://support.microsoft.com/kb/947239 Any further insights are appreciated.
August 9th, 2011 6:32pm

Hi, I'm trying to involve someone familiar with this topic to further look at this issue. Thanks for your patience. Regards, MiyaThis posting is provided "AS IS" with no warranties, and confers no rights. | Please remember to click "Mark as Answer" on the post that helps you, and to click "Unmark as Answer" if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.
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August 12th, 2011 3:41am

What exactly are you looking for? Do you simply want to disable auto tuning? Please provide more details. If you are facing issues with auto tuning, have you tried disabling using netsh interface tcp set global autotuninglevel=disabled 934430 Network connectivity fails when you try to use Windows Vista behind a firewall device http://support.microsoft.com/default.aspx?scid=kb;EN-US;934430 Typically for slowness issues, disabling the feature works. 983528 The TCP receive window autotuning feature does not work correctly in Windows Server 2008 R2 or in Windows 7 http://support.microsoft.com/default.aspx?scid=kb;EN-US;983528 You can also try disabling SNP features on the affectes system and see if it helps, use registry keys from below KB 948496 An update to turn off default SNP features is available for Windows Server 2003-based and Small Business Server 2003-based computers http://support.microsoft.com/default.aspx?scid=kb;EN-US;948496 Sumesh P - Microsoft Online Community Support
August 12th, 2011 9:27am

Thanks for the interest. Here is the basic problem: We now have an ultra-fast fiber network in the faculty area at Stanford: A Google Fiber Beta site, like Kansas City. If I run my Windows Home Server 2011 on the network (same cabling and router) I get 800-900Mbps up and down (Yes.. these numbers are correct). However, when I run my 6x more expensive Dell M4500 runing Windows 7 I get 500mbps up and 150Mbps down. Now, I understand that a normal person would be just happy with these results. But not us as we have a bunch of engineers on the faculty trying to figure out the discrepancy. I have tried every setting for netsh autotuning and at the advice of some experts I eventually settled on the "highly restricted" setting. This intermittantly gets me 500Mbps up and down, but only about 50% of the time. We are testing with: http://netspeed1.stanford.edu:7123/ Which gives us considerable diagnostic information and the change in speed correlates with changes in size of the receive window, which we cannot directly change in W7, but you could in old XP. So, my impression is that since Vista this has been changed so setting cannot be customized. I understand that network conditions change and there is a need for W7 to be flexible and change with conditions, but there are Ph.D.-level electrical engineers from Stanford who have just given up on this... of course mac and Linux boxes as well as Microsoft servers have no problem with the Google fiber system. I appreciate the chance to communicate with some experienced people at MS, but you should run this up the corporate ladder since W7 is not ready for fast fiber netwroks (Google is not the only provider as Fios users seem also to have problems). Insights or supportive psychotherapy appreciated....
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August 12th, 2011 6:32pm

Thanks for the additional details. Please test ALL the solutions listed below 1. Have you tried disabling using netsh interface tcp set global autotuninglevel=disabled ? How was the performance improvement if any? Typically for slowness issues, disabling the feature works. 2. 983528 The TCP receive window autotuning feature does not work correctly in Windows Server 2008 R2 or in Windows 7 http://support.microsoft.com/default.aspx?scid=kb;EN-US;983528 3. You can also try disabling SNP features on the affectes system and see if it helps, use registry keys from below KB 948496 An update to turn off default SNP features is available for Windows Server 2003-based and Small Business Server 2003-based computers http://support.microsoft.com/default.aspx?scid=kb;EN-US;948496 934430 Network connectivity fails when you try to use Windows Vista behind a firewall device http://support.microsoft.com/default.aspx?scid=kb;EN-US;934430 Sumesh P - Microsoft Online Community Support
August 15th, 2011 5:11am

Thanks for the additional details. Please test ALL the solutions listed below 1. Have you tried disabling using netsh interface tcp set global autotuninglevel=disabled ? How was the performance improvement if any? Typically for slowness issues, disabling the feature works. 2. 983528 The TCP receive window autotuning feature does not work correctly in Windows Server 2008 R2 or in Windows 7 http://support.microsoft.com/default.aspx?scid=kb;EN-US;983528 3. You can also try disabling SNP features on the affectes system and see if it helps, use registry keys from below KB 948496 An update to turn off default SNP features is available for Windows Server 2003-based and Small Business Server 2003-based computers http://support.microsoft.com/default.aspx?scid=kb;EN-US;948496 934430 Network connectivity fails when you try to use Windows Vista behind a firewall device http://support.microsoft.com/default.aspx?scid=kb;EN-US;934430 Sumesh P - Microsoft Online Community Support Thanks for the response. 1. I have tried all the settings for autotuning systematically. My rating of success is a connection over 500Mbps up and down.If I set "disabled" the success is about 20%, "restricted" 40% and "highly restricted" 50%. On the WHS 2011 system the system connects at 800Mbps up and down > 90% of the time. When I run the diagnostics side of the http://netspeed1.stanford.edu:7123/ The change in speed correlates with changes in size of the receive window, which we cannot directly change in W7, b"This update is not applicable to your computer">ut you could in old XP. 2. On the KB #1, when I run : Windows6.1-KB983528-x86 I get the error: "This update is not applicable to your computer"... I am running a 32-bit system. I also thought this was the solution. I read the information in the KB article and it looks like the hot fix replaces a couple files see below (I CANNOT FIND THESE FILES ON MY MACHINE?): Windows 7 and Windows Server 2008 R2 file information notes Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to. The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature. For all supported x86-based versions of Windows 7 File name File version File size Date Time Platform Fwpkclnt.sys 6.1.7600.16385 187,472 14-Jul-2009 01:20 x86 Tcpip.sys 6.1.7600.20712 1,288,576 12-May-2010 09:20 x86 So, I do not see either of the above files on my machine... but maybe I am looking in the wrong directories. 3. Seems to apply to Server 2003, not Windows 7. The second link just turns off the autotuning. So, looks like the only hope might be the Hotfix, but I cannot get it to work. Thanks again.
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August 15th, 2011 10:12am

Ok, you need a dev to get and set the receive buffer size, it's not me ;-) http://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient.receivebuffersize.aspx Let us know the fix. The tool suggested an increase for this machine.
August 15th, 2011 10:48am

Please try below steps in the given order: 1. I have tried all the settings for autotuning systematically. My rating of success is a connection over 500Mbps up and down.If I set "disabled" the success is about 20%, "restricted" 40% and "highly restricted" 50%. On the WHS 2011 system the system connects at 800Mbps up and down > 90% of the time. So you have tried disabled, restricted and highly restricted setting. Have you tried "normal" and "experimental"? These allow the receive window to grow. After running the command, make sure that the setting has changed and shows the new setting. IF that doesnt work, try again after you turn off heuristics netsh interface tcp set heuristics disabled then set to disabled netsh interface tcp set global autotuninglevel=disabled else try normal or experimental setting netsh interface tcp set global autotuninglevel=normal 2. On the KB #1, when I run : Windows6.1-KB983528-x86 I get the error: "This update is not applicable to your computer"... I am running a 32-bit system. I also thought this was the solution. I read the information in the KB article and it looks like the hot fix replaces a couple files see below (I CANNOT FIND THESE FILES ON MY MACHINE?): This is for Win7 RTM. Are you already on SP1? 3. Seems to apply to Server 2003, not Windows 7. The second link just turns off the autotuning. Yes, the hotfix itself is for w2k3, however i just want you to put in the registry settings from the KB. That would be Click Start, click Run, type regedit, and then click OK. Locate the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters Right-click EnableTCPChimney, and then click Modify. In the Value data box, type 0, and then click OK. Right-click EnableRSS, and then click Modify. In the Value data box, type 0, and then click OK. Right-click EnableTCPA, and then click Modify. In the Value data box, type 0, and then click OK. Exit Registry Editor, and then restart the computer. Sumesh P - Microsoft Online Community Support
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August 15th, 2011 10:51am

Thanks for the help. Nano Warp, I am not a stranger to coding and have Visual Studio Pro. I am just concerned that if you write the code, Windows 7 will reset any changes you do. It would be nice if the MSFT engineer would comment on that. In any case, I will systematically follow his prescription tonight I hope and see what happens. For the MSFT engineer, I did verify that all the autotunning chnages took. I will see what the "heuristics" command does, but I think I have changed it. Perhaps not systematically. I am already on SP1 of W7. I will do the registry settings after I check the heuristics. Thx
August 15th, 2011 7:51pm

Well I did the registry edits and systematically changed the heuristics and autotuning settings. Performance did not change. I guess all that is left is to write a program as suggested by Nano Warp, but would like to know if the MSFT engineer thinks this is worth a shot. I can do these things but will take a few hours. This code snippet seems like something to go within a program that is doing reads and writes, rather than to set a system parameter, but i may be wrong.
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August 15th, 2011 11:32pm

By writing a program you can SET the window to a value X of your choice. The above settings we tried do not allow you to SET the window to a specified size, however should have altered the behavior and limits of the receive window. Here are some additional suggestion after I discussed the issue internally with my colleagues: 1) If your router has wireless capabilities make sure the binding order is correctly listing the wired NIC as the primary network adapter. If the wireless NIC is primary in the binding order you will be limited to 802.11[x] speeds. Given your speeds off the laptop that could be the issue since 802.11n works is approximate intervals of 150Mbps (150, 300, 450, 600). - Open "Network and Sharing Center" - "Change Adapter Settings" from the left column. - Press the ALT key to bring up the old legacy menu. - Advanced > Advanced Settings... - Make sure "Local Area Connection" (or whatever the wired network connection is called) is at the top of the list and wireless is below it. Use the up/down arrows on the side of the Connections dialog to change the order. - Restart the browser you're running speedtest.net in so a new connection on the wired NIC is used for the next run. ...if this is the case I would recommend turning back on the receive window auto-tune level. netsh interface tcp set global autotuninglevel=normal 2) Enable Compound TCP. It usually gives a slight performance boost on high speed networks. netsh interface tcp set global congestionprovider=ctcp 3) Update the NIC drivers: http://support.dell.com/support/downloads/driverslist.aspx?c=us&cs=04&l=en&s=bsd&ServiceTag=&SystemID=PREC_M4500&os=W764&osl=en&catid=&impid= Sumesh P - Microsoft Online Community Support
August 17th, 2011 7:10am

I appreciate the effort, but the settings changes and driver re-install did not help. The wireless connection was on top and I did relegate it to the bottom. The router was changed with the new network. I wonder if I can delete all the LAN and WiFi settings and if they would be reconstructed? I will take a shot at the programming over the weekend as I have a long plane trip. It does not look hard, just a question if the sucker will compile etc. I have some extensive c++ programs I can put back on this machine and make sure they compile first, them make a new one for this problem.
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August 17th, 2011 11:17pm

I wonder if I can delete all the LAN and WiFi settings and if they would be reconstructed? The last device installed always ends up on the top of the binding order. An easier test would be to disable WiFi and then test. That would force the connection to the wired NIC. You disable the network device at that "Change Adapter Settings" window from above. Select the wireless NIC and click "Disable this network device" from the menu under the address bar. Select again and click "Enable this network device" to turn it back on. As for autotuning, WHS2011 is built on the Windows Server 2008 R2 core. It's basically a stripped down 2008 R2 server with different features and limitation. That means WHS2011 will have the same TCP/IP stack and autotuning abilities/settings that Win7 has. If you got 800-900Mbps up and down off WHS2011 then you should get the same off Win7 with default settings.
August 19th, 2011 9:58am

I wonder if I can delete all the LAN and WiFi settings and if they would be reconstructed? The last device installed always ends up on the top of the binding order. An easier test would be to disable WiFi and then test. That would force the connection to the wired NIC. You disable the network device at that "Change Adapter Settings" window from above. Select the wireless NIC and click "Disable this network device" from the menu under the address bar. Select again and click "Enable this network device" to turn it back on. As for autotuning, WHS2011 is built on the Windows Server 2008 R2 core. It's basically a stripped down 2008 R2 server with different features and limitation. That means WHS2011 will have the same TCP/IP stack and autotuning abilities/settings that Win7 has. If you got 800-900Mbps up and down off WHS2011 then you should get the same off Win7 with default settings. Thanks for the comments. Will try your disable strategy. Yesterday I had a call from a Google engineer and discussed this at length. This stimulated the idea that I bring home a similar brand new dell laptop to test. Well, long and short of it is that the out of the box M2400 did the fast downloads consistently (80% of the time) and has a very similar NIC card (Intel 82567LM versus 82577LM in the M4500) . This supports your idea that it has the same TCP/IP stack as the WHS2011. The I checked its autotuning etc. tcp/ip setting and changed the bothersome laptop's (M4500) settings to the same, but there was no improvement. I was unable to check where the heuristics setting was on the M2400. I also checked the drivers and the M2400's drivers were older (2009), the M4500 does not roll back that far. To test if it were a driver issue I installed the latest drivers and Intel management software on the M2400 and it did not slow down. I then made sure every setting on the M4500 matched every setting on the M2400. Currently at a loss, but it is looking to be more the Intel NIC card than W7. Cheers
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August 19th, 2011 1:25pm

Did you have any luck testing with WiFi disabled?
August 23rd, 2011 9:34am

Did you have any luck testing with WiFi disabled? Nope. Made no difference. I m sorta giving up. Because the connection goes back and forth, I think it must be the autotuning. I looked into the programming solution, and I can do it. i just do not have the time to mess with it and I think any settings changes I made would be over-ridden by the MS OS. Of course the server I have just runs rock solid at the higher rate. Still a mystery, but given the number of entries on Google, I think it is the autotuning.
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August 23rd, 2011 12:27pm

netsh int ip set global taskoffload=disabled This will disable all the Windows TCP offload providers (RSS, TCP Chimney, Auto Tuning, etc.). If it's Windows 7 offloading related this should fix it.
August 23rd, 2011 12:45pm

Thanks for the help everyone. Eventually this worked. MS updates were overwriting the latest drivers from Intel.... Windows Updates drivers were much older than Intel's. Google set up a new test site. So this is what it looks like.
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August 28th, 2011 7:38pm

Thanks for the update, and congrats on the Gb fiber. I am officially jealous of you now ;) I'm stuck on a local, small area monopoly and get a whopping 10Mbps down and 762 Kbps up.
August 29th, 2011 9:19am

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