Tuesday, November 18, 2014

Intel Wireless AC 7260 Problem and Work-around

I got a new laptop at work and it has the Intel AC 7260 wireless card. Apparently, it does not like our AC access points here. With the default settings, my iperf tests look like this:

iperf\iperf.exe -c server -r -i 2 -w 524288
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  512 KByte
------------------------------------------------------------
------------------------------------------------------------
Client connecting to server, TCP port 5001
TCP window size:  512 KByte
------------------------------------------------------------

[ ID] Interval       Transfer     Bandwidth
[  4]  0.0- 2.0 sec  24.0 MBytes   101 Mbits/sec
[  4]  2.0- 4.0 sec  24.1 MBytes   101 Mbits/sec
[  4]  4.0- 6.0 sec  30.2 MBytes   127 Mbits/sec
[  4]  6.0- 8.0 sec  30.8 MBytes   129 Mbits/sec
[  4]  8.0-10.0 sec  28.1 MBytes   118 Mbits/sec
[  4]  0.0-10.0 sec   137 MBytes   115 Mbits/sec

[  4]  0.0- 2.0 sec  6.67 MBytes  28.0 Mbits/sec
[  4]  2.0- 4.0 sec  6.87 MBytes  28.8 Mbits/sec
[  4]  4.0- 6.0 sec  4.33 MBytes  18.2 Mbits/sec
[  4]  6.0- 8.0 sec  6.17 MBytes  25.9 Mbits/sec
[  4]  8.0-10.0 sec  6.05 MBytes  25.4 Mbits/sec

[  4]  0.0-10.1 sec  30.4 MBytes  25.2 Mbits/sec

If I change the HT Mode from VHT Mode (AC) to HT Mode (N) in the driver properties, then my results get much better.

[ ID] Interval       Transfer     Bandwidth
[  4]  0.0- 2.0 sec  33.4 MBytes   140 Mbits/sec
[  4]  2.0- 4.0 sec  30.6 MBytes   128 Mbits/sec
[  4]  4.0- 6.0 sec  33.0 MBytes   138 Mbits/sec
[  4]  6.0- 8.0 sec  33.0 MBytes   138 Mbits/sec
[  4]  8.0-10.0 sec  34.4 MBytes   144 Mbits/sec
[  4]  0.0-10.0 sec   164 MBytes   138 Mbits/sec

[  4]  0.0- 2.0 sec  25.8 MBytes   108 Mbits/sec
[  4]  2.0- 4.0 sec  30.9 MBytes   130 Mbits/sec
[  4]  4.0- 6.0 sec  29.6 MBytes   124 Mbits/sec
[  4]  6.0- 8.0 sec  30.7 MBytes   129 Mbits/sec
[  4]  8.0-10.0 sec  31.3 MBytes   131 Mbits/sec
[  4]  0.0-10.0 sec   149 MBytes   124 Mbits/sec

I see the same sort of results with Speedtest.


4 comments:

  1. Brick you might want to do the following. I dont know if your using reference or oem or windows drivers. I would goto www.intel.com goto menu support then automatically find drivers and software install the latest driver for you wireless direct from intel. Let me know if it lets you chip go back into AC mode and not N mode.

    http://driveragent.com/c/archive/e04cf023/image/11-0-103/Intel-Wireless-LAN-Driver-version-v16.1.4.4

    ReplyDelete
    Replies
    1. Mike,

      Thanks for the thoughts. I've used both the Intel Driver Update Utility and Dell's System Detect tool to make sure I've got the latest driver. I'm current at 17.1.0.19. I've not tried any older versions. When things slow down, I'll work with one of the wireless guys here to see if we can figure out what is happening. He can look at the controller and see the details of my connection from his side while I look at the client.

      Cheers!

      Delete
  2. Another option might be a firmware update on the AP and also look into the encryption you are using. WPA or WPA2. What is the make and model of the access point?

    ReplyDelete
    Replies
    1. They are Aruba 225 devices. We are scheduling an update soon - waiting for the latest GA version.

      Delete