Debugging latency, spikes and lag on certain Intel Centrino wifi card and driver combinations-English Community

Debugging latency, spikes and lag on certain Intel Centrino wifi card and driver combinations

Symptoms

When reading this article, you are experiencing sporadic & recurring connection dropouts or latency spikes on Wireless-N (802.11n) networks. Switching to Wireless-G (802.11g) solves the latency/lag spikes and/or recurring connection dropouts.

Lag spikes during games, usually they happen every minute. This is highly dependant on the game engine. Some games may be able to correct the latency spike using interpolation.
Slow internet browser
VOIP software (Skype, Google Hangout) sometimes hangs for a few seconds

More information:

https://communities.intel.com/message/178955

Diagnosis

Affected Intel WLAN adapters:

Intel Centrino Advanced-N 6200
Intel Centrino Advanced-N 6205
Intel Centrino Advanced-N 6235
Intel Centrino Advanced-N 6250
Intel Centrino Advanced-N 6300

Operating systems:

Windows 8
Windows 8.1

Affected drivers:

Driver versions: 15.x, 15.xx
Latest Intel PROSet tested at time of writing: 16.11.0

Make sure to continue below to perform a diagnosis!

This is not the same as Intel PROSet's version. For example: Installing Intel PROSet 16.7.0, will install driver 15.10.5.1 on Windows 8.1, look here for more information)

Wireless networks:

802.11n: your network must be running in 802.11n mode.

How to determine whether you are affected by actually testing. (advanced users)

In Command Prompt enter 'ping www.google.com -n 150'.
This will ping www.google.com 150 times.

Depending on Roaming Sensitivity it may scan more often or less often. In the screenshot above we observe a lag spike of approximately 3 seconds.

Solution

Windows 8 only

WARNING: This solution may not work on all wireless cards. Some wireless cards may not be supported on driver version 14.x

This solution is recommended for Windows 8 users at time of writing. Users can always test newer drivers and then revert to the inbox Windows 8 driver.

Revert back to driver branch 14.x, this can be done by uninstalling all Intel drivers when a driver with version 15.x is installed.

Windows 8.1 and Windows 8's second solution (advanced users)

This solution is for advanced users. The advantage of this solution is that you can always use the latest up-to-date driver. A disadvantage is that your wireless card won't scan for other networks when connected, your list of wireless networks may or may not be up to date when connected.

Press Windows key + R
Enter 'regedit

Navigate to HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > Class > {4d36e972-e325-11ce-bfc1-08002be10318}
Now you see a list of folders: 0001, 0002, 0003 and so on... Click each folder until you see a key named 'AdapterModel' containing the name of your WLAN adapter.
Scroll to the bottom until you find a key named 'ScanningWhenAssociated', Change its value to 0
Now reboot your computer.

NOTE: When installing new drivers, the value of ScanningWhenAssociated may automatically return to 1

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Comments

jdyck On 2014-08-02, 10:53 AM

It seems there are a ton of people with this problem, and this is the first actual solution I have found to it - nice work!

Some people are forcing the wireless adapter to work only in wireless G mode, which gets rid of the ping spikes, but of course prevents wireless N mode. Others are doing various forms of magical incantations, but no one else seems to have solved this correctly.

One thing to note is that I actually had two separate registry folders for my wireless network adapter - I first changed "ScanWhenAssociated" back to 0 on the first one, and it didn't make a difference. Searched again, found a second folder for my network adapter, changed "ScanWhenAssociated" to 0 on the second one, rebooted, and voila - no ping spikes!

Thanks for this excellent post.