802.11 ac on 5ghz tx rate drops to 7mbps

I have PRECISELY the same issue on my MacBook Pro (Mid 2012). I have a couple other Macs in the house also on the 5ghz network and when I have the 7mbps issue, I've hopped on those and there's no problem whatsoever. I've gone through multiple support calls and even brought it to the genius bar but the issue remains.

Things we've tried:

1. Restarted router (Airport Extreme w/ 802.11ac)
2. Resetting PRAM
3. Resetting SMC
4. Removing networking preference files
5. Reinstalling OS
6. Hardware test (no flags)
7. Repairing permissions
8. Removing all saved wifi networks

There are probably others but the bottom line is that none of those solved the issue. The only fix is to switch over to the 2.4ghz network but that's just temporary in that I want to be on the network with less interference (5ghz). Anyone out there who can help?

Try changing the channel the 5 GZ signal is using.

It's currently set to Automatic for both 2.5 and 5.

Would this still hold up as a solution even though only the one computer is having the issue? All other computers in the house (iMac, MacBook) haven't ever had this issue and they all connect to the same base station.

Mine too - 5 bars all the time. I thought it was DiscoveryD that was mucking things up but the update to the latest version Yosemite (with mDNS responder replacing it) didn't really help at all with this specific issue.

Good to know that they're hopefully fixing it in El Capitan.

I've been on El Capitan for about two days now (public beta GM) and from what I can tell, it's fixed! I cleared my DNS cache just to be safe (using CleanMyMac 3), but other than that, I haven't done anything differently. So far, so good!

You do not need to use cleaning programs. They can destroy your computer operation.

CleanMyMac - Uninstall

CleanMyMac2 Un-install

CleanMyMac 3 Uninstall

After un-installing, use this program to make sure you got all the pieces.

EasyFind – Spotlight Replacement

cerarz wrote:

Signal is flawless in my case as when using Windows 8 on that same mac it works like a charm. I provided feedback in el capitan beta and they answered to try it with the latest version. Unfortunately I downgraded before to yosemite because Office crashed when trying to save files.

The issue is that the signal speed is a historical value reached due to past experience with retransmits, interference, etc. and may not reflect the status of the connection at any particular moment.

So, for example, if there was interference degrading the connection for the past hour, but it then disappears, the other computers won't necessarily see an issue, but if your computer was trying to send or receive data it will have "downshifted" to the fastest speed at which it could reliably transmit/receive data.

Changing channels is the best approach, or reboot your router.

(The "automatic" setting on AirPort picks a channel based on signal conditions at the time it boots, it doesn't change it if it later finds interference.)

Same thing was with my rMBP15 late 2013 until yesterday. Problem with 802.11ac started after Yosemite 10.10.2. 10.10.3 and all followed did drop on 5 Ghz network as you described , 2,4 Ghz was OK ,217 Mbps with no drops.Thanks to Time Machine I tried all followed and then returned back to stable 10.10.2. Now I am on El Capitan 10.11.1. Yesterday I started experimenting with changing of regional codes on my Airport Extreme router, after I have changed settings to EG from RU region ,I have now 405 Mbps. It is floating from 600 Mbps to 270 Mbps. Before that on my local RU after 1 minute speed drop from 405 to 7Mbps with no access to internet. So result as on 10.10.2 I had with no drops. I will return back to my country code later when new version of OS be available to check if WiFi issue with 5 Ghz network corrected.

PS: I have Mac mini late 2014, it work fine on all version of OS, it is strange as rMBP late 2013 and Mac mini late 2014 have the same WiFi card according to ifixit web page

My new MacBook 12-inch, early 2015 join the 5G network with 802.11ac has the same problem. Now I am on El Capitan 10.11.2, Tx rate speed drop from 174 to 7Mbps with no access to internet.

But i command " sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resourc es/airport -s " .

Found all country code are the same.

how can i do? 😢 please forgive my terrible english.

Use Wireless Diagnostics to help you resolve Wi-Fi issues on your Mac - Apple Support

Beside actual diagnostics, the Wireless Diagnostics -> Window -> ... has a but of other features.

Scan will tell you about other WiFi base stations near you, and will give RSSI and Noise information for each.

The line in Bold will be your WiFi base station.

You want to see a strong RSSI signal (-30, -40, -50's)

You want to see a low Noise signal (-92, -80's)

You also want to check the channels being used by yourself and the other WiFi base stations. If you are using 2.4GHz, then you want to be 5 channels away from any other base stations (each channel uses 5 channels worth of bandwidth, which is why you need to be 5 channels away to get a clear signal). If you cannot get 5 channels away, then have your WiFi base station use a channel that is between 2 other base stations with weak signals and where you get low noise and a strong signal for yourself.

If you are using 5GHz, each channel does not overlay, but 5GHz can gang 2, 3 or 4 channels together for faster transmissions. But 5GHz is also shorter range so there is a better chance you will not see a lot of noise from other base stations. Of course this assumes you are not far away from your own WiFi base station as you need to get a strong signal.

Other sources of noise are cordless telephones that use 2.4GHz or 5GHz frequences. Baby Monitors are very bad as they are on all the time. Microwave ovens operate at 2.4GHz because that is the frequency that causes water to vibrate. And for that reason putting your WiFi base station behind a fish tank full of water is a bad idea, as water will absorb the signal. Metal objects between your base station and your Mac, including metal studs in the walls and concrete walls with structural metal rebar in them. Metal appliances, so do not put your base station where it has to go through the refrigerator, stove, hot water heater, etc...

USB-3 devices with poorly shielded cables or poorly shielded enclosures can cause serious WiFi interference, especially if it is sitting right next to the Mac or the WiFi base station. intel wrote a white paper on this.

<https://www-ssl.intel.com/content/www/us/en/io/universal-serial-bus/usb3-frequen cy-interference-paper.html>