T420 / Centrino 6300 Wireless Issues

Hi guys,
I have a Thinkpad T420 with Intel Centrino 6300 wireless. This thing is brutally slow in Windows 7.

I bought the wireless card on Ebay - but I am pretty sure this is a genuine card. My BIOS whitelist accepts the card and this is only a Windows 7 problem. When I run a Linux Mint live session I get download speeds that are many times higher on the same machine. This would seem to rule out antenna or installation issues, or a router issue (Netgear WNDR3700V2).

On two older machines I get much better results as well.

These are my download test results comparing 3 laptops next to each other - all situated 25ft and two floors away from my router (which is in my basement):

Tested at speedtest.cogeco.net (not my internet provider):
1. Thinkpad T420, Intel Centrino 6300 running Windows 7: 415 Kbps
2. Thinkpad T420, Intel Centrino 6300 running Linux Mint 12: 6900 Kbps
3. Acer Aspire 5570, Atheros AR5008 running Windows 7: 7718 Kbps
4. Acer Aspire 5570, Atheros AR5008 running Linux Mint 11: 7021 Kbps
5. HP Pavillion ZV5000, Atheros AR922X running Windows XP: 7441 Kbps

I have done just about everything I could think of to try and resolve this situation.
- Running latest driver 14.2.0.10 (downloaded from Lenovo) plus a succession of earlier drivers as well (downloaded directly from Intel).
- Adjusted all advanced wireless settings to those recommended by Intel.
- Uninstalled Lenovo Power Manager drivers and application, tested with same results and re-installed.
- Played around with Lenovo Power Manager settings (the version 3.64 installed no longer has settings to adjust wireless directly).
- Installed Intel PROSet Wireless utility and messed around with settings there. Uninstalled when it made no difference.

This has me completely stumped. Any ideas out there?

 

You could try toggling some Advanced options via the Device Manager to see if it helps. Type in Device Manager at the search bar, then choose Network Adaptors. Highlight the Intel Centrino 6300AGN adaptor then right-click and choose properties. There should be a tab called Advanced Options, if your router supports N band try enabling it if it wasn't on. You can also try toggling the Transmit Power to Highest setting and the Roaming Aggressiveness to see if it makes a difference.

 

I already tried playing with all those settings - no luck. They are currently on Intel's recommended settings. The poor performance occurs in Windows 7 when connected to my routers' 2.4GHz and 5GHz bands.

 

What speed do you see at Speedtest.net - The Global Broadband Speed Test ?

 

At internetfrog speed test I get a round trip time (ping) of over 6 seconds and a download speed of 0.36Mbps in Windows 7 vs 1.23 seconds and 6.9Mbps in Linux Mint 12.

 

Cross-posting is generally frowned upon in online forums, and against the rules at NBR. I've merged your threads into the one here in the Lenovo/IBM subforum, but if you would prefer moving it to the Networking subforum, please use the Report feature ( ) and let us know.

Ontopic: Have you tried completely uninstalling the actual driver, ensuring that all remnants are cleaned out using Revo Uninstaller or CCleaner and reinstalling the latest revision?

 

2.50Mbps in Windows 7 (with 545 ms ping); 12.94 Mbps in Linux Mint (with 45ms ping).

It looks like the wireless adapter "runs out of steam" during speed testing. At speedtest.cogeco.net the download speed is relatively quick during 1.9MB and 2.9MB tests; then the 5.9MB test totally bogs down. In linux mint the download speed is quick all the way through to the 11.7MB test.

 

Tried a complete uninstall of everything wireless followed by fresh install. Results are unchanged.

Any idea which version of Lenovo Power Manager I need to be running to have the "Wireless adapter settings" available for manipulation to "Maximum Performance"? Version 3.64 doesn't have the settings present. Or is this a lack of driver support?

 

I don't see those options in Power Manager. Have you checked the Advanced Settings for the device properties in Device Manager? My 6300 seems to run OK with these settings:



John

 

John, thanks. My settings are the same as yours except I have my 2.4GHz channel width on "Auto" now (my router transmits at 40MHz on it's 2.4GHz band) - but I used the default settings initially (restricted to 20MHz). In W7 it is slow on both 2.4 and 5GHz; in Linux it performs as expected on both bands.

 

Can you try testing your Windows performance when close to the router? If that makes a difference then it points to the power setting and if it doesn't make any difference then it points to some other setting(s).

The other thing to try is changing the router channel. There's no obvious reason why the Linux driver would be better able to handle interference from another router, but sometimes these things happen.

John

 

My trials and tribulations will have to wait until after new year - I am lying on a beach in the Caribbean instead of fiddling with my Thinkpad's wireless settings.

I'll try playing with the channels; if that fails I'll bite the bullet and do a clean install of Windows 7.

Thanks.

 

In case this helps anyone else, I managed to get my Centrino 6300 working well under Windows 7 by Disabling 802.11n Mode under Advanced options in Device Manager. I am getting 14.2Mbps at speedtest.net and 8813kBps at speedtest.cogeco.net (25ft and 2 floors above my router - when I place the laptop 3ft away from the router I get 18.75Mbps).

Of course, having to disable N mode means I am limiting wireless throughput to 54Mbps - making my upgrade to the Centrino 6300 a waste of $40.

 

Enable the n-setting again and this time try to disable ipv6.

 

When I do that I am back to the crappy results of my initial post.

 

Try Ubuntu from an USB stick. If you still have the same problem in Ubuntu so is it probably an hardware issue.

 

Read my first post - this is not hardware; it's Windows 7.