Cisco AP 2800 - Intel 8260NGW

[polskifacet]

Hi guys, 

I’m writing to you if you have advice for a weird problem I have here with a bunch of new Lenovo Yoga P40 (with wireless card Intel 8260NGW) working on wireless.

This is the problem:

• When the computers join an access point Cisco 1040 and radio 801.11bn, no problem: download fast (30/50 Mbps), upload fast (50 Mbps)
• When the computers join an access point Cisco 2800, the radio move to 801.11ac: download slow (0.5 Mbps), upload fast (50 Mbps)
• I forced the wireless card to radio 801.11bc: download slow (0.5 Mbps), upload fast (50 Mbps)
• I tried dozen of advice from forum and website in internet, changing wireless card settings, removing app: download slow (0.5 Mbps), upload fast (50 Mbps)
• I tried to change the wireless card with an Intel 7265NGW, nothing better
• I updated the controller to IOS 8.4.100.0, nothing better
• I reset Windows 10, nothing better
• I installed Wndows 10 by scratch, all fixed

Have you ever seen something like that in your experience?

 Thank you

Luciano

[Philip D'Ath]

I have had lots of issue with wireless NIC drivers.  Intel went through a bad patch of bugs as well.

Try installing the latest wireless NIC driver for your Yoga's and see if that makes an impact.

[Leo Laohoo · Accepted solution]

I reset Windows 10, nothing better
I installed Wndows 10 by scratch, all fixed

Wait, is this machine running on Windows 10 Creator's Update?  If the answer is yes, then there is a known bug with Win10CU which severely impacts wireless performance.  

There are several known workarounds (thanks to Scott for sharing the link) which can be found HERE.

[patoberli]

I hope this issue will be fixed in (another) a future Intel Wi-Fi driver update, but currently only the workaround found in the Microsoft forum helps.

[patoberli]

Update has been released by Microsoft in the update kb4022716 released on 27.June.2017:

https://support.microsoft.com/en-us/help/4022716/windows-10-update-kb4022716