Local Area Network : How to fix slow LAN transfer speed of files in Windows

fixing-slow-lan-speed

Recently I had to solve a problem of a very slow transfer of files between two computers on a LAN network using an Ethernet cable. Both machines had Windows 7 x64 installed and the transfer speed was ridiculously slow at 10-15kb/s. Using Task Manager under Networking tab, Network Utilization was showing only around 0.25% for Local Area Connection.

I looked around the web for solutions and found quite a few suggestions on how to tackle this problem. Those that I tried and the one that finally solved my problem are discussed here.

Turning off "Remote Differential Compression"

One of the first suggestions that I came across was to turn off this Windows Feature in Windows 7.

Windows 7 features options

This suggestion is common on the web but it turns out to be just a myth.

From TechNet:

This is 100% false. Neither Windows Update or file copy operations use RDC at all. 

So I ignored this suggestion and continued looking.

Disabling "TCP Auto-Tuning"

This is another common suggestion that I came across and it uses NETSH command-line utility used for displaying and modifying the network configuration. To make the necessary changes, we need to run that utility as an Administrator.

command prompt - running as administrator - netsh

  1. Open Command Prompt as Administrator:
    • Click on Start Menu
    • Type Command in search box
    • Command Prompt will show up in results. Right-click on it to open Context Menu
    • Select Run as administrator
    • If User Account Control Window shows up asking if you want to allow the following program to make changes, select Yes
  2. Type: netsh interface tcp set global autotuning=disabled
  3. Restart the computer
  4. To verify that the auto-tuning is still disabled type in Command Prompt:
    netsh interface tcp show global

This suggestion still didn't solve my problem, so I looked further, but before doing that I wanted to set Auto-tuning back to the default value by typing netsh interface tcp set global autotuning=normal in the Command Prompt (running as an Administrator).

Disabling "Large Send Offload (LSO)"

Large Send Offload / LSO is a technique of improving network performance while at the same time reducing CPU overhead. Apparently, it does not work very well, so it was suggested to disable it.

LSO is an option located in a Device Manager under your network adapter, so this solution requires Administrator Privileges.

windows 7 - network adapter - advanced tab

Follow these steps:

  1. Open Start Menu, right-click on Computer and select Properties
  2. Under Control Panel Home located on the left side of the window click on Device Manager
  3. You will get a list of all devices on your machine. Expand Network Adapters.
  4. Find your Network Card and double-click on it.
  5. Select Advanced tab. You will get a list filled with different options.
  6. Select Large Send Offload V2 (IPv4) and set the value to Disabled
  7. Do the same for Large Send Offload V2 (IPv6) if it is available
  8. Click OK

After clicking OK, I tried to send a file over the LAN network. The transfer speed started very slow, but it was gradually picking up speed. I decided to restart the computer and try to send that file again and this time it worked like a charm.

Now that sending of files worked as it should, I also checked the speed for receiving files. It turned out that it was still slow but all I had to do to fix that was to disable Large Send Offload V2 on the other computer. Once done,  the problem was solved for receiving files as well.

Conclusion

In this post, we examined different ways to solve slow speed on a LAN network. One of them is just a common myth, but for the other two you need to have administrator privileges. I hope you found this article useful. Consider sharing it on a social networks. Comments are also welcome.

If you solved your slow LAN speed problem in a different way, let me know how and I might add that solution to the list.

144 Comments

Click HERE to add your Comment
  1. Yann Takvorian
    July 29, 2013
    • gaus
      January 13, 2014
      • admin
        January 17, 2014
        • Neil
          February 19, 2017
        • George
          April 10, 2019
      • macns
        May 30, 2014
      • Ambidexter
        January 14, 2017
        • CleJons
          July 20, 2018
    • Isa
      April 9, 2017
    • Manasan
      October 27, 2018
    • Earl M Miller
      August 7, 2020
    • Christian R
      September 13, 2020
    • tom k-w
      July 13, 2021
  2. Santoxthanksyou
    August 21, 2013
  3. Domy
    August 26, 2013
  4. admin
    August 26, 2013
  5. Adam
    September 3, 2013
    • Rangaraj
      October 27, 2013
  6. Tony
    September 9, 2013
    • sunil vishwakarma
      May 5, 2014
  7. castiel
    September 13, 2013
  8. Tord
    October 9, 2013
  9. stephen tidwell
    October 28, 2013
    • arun
      January 17, 2015
      • Kapil
        June 1, 2022
  10. RoamingChile
    October 29, 2013
  11. Chris
    November 2, 2013
  12. Buyoy
    November 6, 2013
  13. Peter Forster
    November 12, 2013
  14. Leonard Lay
    November 30, 2013
    • Alex
      December 19, 2018
  15. dima
    December 15, 2013
  16. Paul
    December 18, 2013
  17. Mish
    December 20, 2013
  18. Jon
    January 11, 2014
    • admin
      January 12, 2014
    • mehrdad
      September 13, 2016
    • Rob T
      April 5, 2017
  19. Gamal
    February 9, 2014
    • M@rino
      February 11, 2014
  20. Amir
    February 13, 2014
  21. Thom
    February 23, 2014
  22. Ole Dufour
    February 26, 2014
  23. ramakrishna
    April 12, 2014
  24. Kali
    April 22, 2014
  25. Dredzed
    April 23, 2014
  26. John Triantafyllou
    April 24, 2014
  27. nolsen
    April 29, 2014
  28. Lance
    June 2, 2014
  29. Chris Mayell
    June 5, 2014
  30. Sayan
    June 17, 2014
  31. Dario
    June 18, 2014
  32. Mehmet
    July 6, 2014
  33. Luka
    July 7, 2014
  34. Behzad
    July 11, 2014
  35. Jane V.
    July 16, 2014
  36. Tom
    July 31, 2014
  37. Paul
    August 15, 2014
  38. Abe
    August 30, 2014
  39. sean
    August 31, 2014
  40. cheezdawg
    September 2, 2014
  41. Kyle Bultman
    October 10, 2014
  42. Kristoffer Lynch
    October 21, 2014
  43. Aidan
    October 29, 2014
  44. Nagababu
    December 2, 2014
  45. dave
    December 19, 2014
  46. Kelly Schneider
    December 24, 2014
  47. Kien
    December 30, 2014
    • admin
      December 30, 2014
      • Ash Nallawalla
        February 6, 2015
  48. Brian
    January 4, 2015
  49. Frank
    January 14, 2015
  50. KERR
    February 25, 2015
  51. Kent Clark
    March 21, 2015
  52. Robin
    April 19, 2015
  53. dave
    May 2, 2015
  54. Warren C
    May 4, 2015
  55. Dieselsolutions
    May 4, 2015
  56. Jur
    May 27, 2015
  57. GA FRANK
    June 18, 2015
  58. mana
    July 31, 2015
  59. xxx
    August 9, 2015
  60. Karan
    August 14, 2015
  61. Mahendra Wardana
    August 25, 2015
  62. Saylee
    August 25, 2015
  63. Justaguy
    January 24, 2016
  64. Anthony
    February 10, 2016
  65. Buzz
    March 15, 2016
  66. Jay
    March 31, 2016
  67. Some Guy
    April 7, 2016
  68. Slow Man
    May 2, 2016
  69. John Doe
    July 23, 2016
  70. Diyadulquer
    July 30, 2016
  71. ali
    September 6, 2016
    • admin
      September 7, 2016
  72. Costa Zachariou
    September 8, 2016
    • admin
      September 8, 2016
      • Costa Zachariou
        September 9, 2016
  73. Saleh
    September 10, 2016
  74. Robert
    September 22, 2016
  75. Srini J
    October 27, 2016
  76. Sagar
    November 30, 2016
    • admin
      November 30, 2016
  77. Malik Khayyam
    December 2, 2016
  78. David
    February 1, 2017
  79. Mike
    February 17, 2017
  80. okehrecords67
    April 23, 2017
  81. Hritwik Jadhav
    May 6, 2017
  82. Rajput
    May 9, 2017
  83. Bharath
    May 29, 2017
  84. Chibueze Iwuala
    June 8, 2017
  85. TSH77se
    September 17, 2017
  86. Nadeem Gul
    September 18, 2017
  87. bill
    October 5, 2017
  88. Wormpower
    November 25, 2017
  89. Dino
    November 28, 2017
  90. stedd
    January 7, 2018
  91. Masha
    February 1, 2018
  92. Hieu ta
    July 3, 2018
  93. Max
    July 12, 2018
  94. ALEX VINOTH
    September 20, 2018
  95. Alt
    October 7, 2018
  96. flown
    November 8, 2018
  97. Michelle
    December 27, 2018
  98. Robert Powers
    May 26, 2019
  99. lemoncurry
    June 28, 2019
  100. Kate
    September 7, 2019
  101. Vincent Duvernet
    October 14, 2019
  102. wasim shahzad
    December 5, 2019
  103. Ian McLellan
    January 20, 2020
    • admin
      January 20, 2020
    • Adam Lepczak
      January 26, 2020
  104. Prakhar Chawda
    April 27, 2020
  105. Cassio L Z F Felippe
    May 13, 2020
  106. Jeff
    July 21, 2020
  107. MC
    August 29, 2020
  108. yourhighnes
    October 22, 2020
  109. Sualdam MacSamildanach
    December 2, 2020
    • Sualdam MacSamildanach
      December 9, 2020
  110. Shridhar maniraj.
    May 30, 2021
    • Sualdam MacSamildanach
      June 7, 2021
  111. James
    June 12, 2021
  112. rad
    October 16, 2021
  113. slowpoke
    April 27, 2022

Write a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.