Wifi is incredibly slow on OS X El Capitan

Yes you are right - as I mentioned earlier:

I can understand that some systems have problems after an upgrade.

But in my case (and that's also the case for other people here) we are talking about a clean install and that's why this is certainly a bug, since no third party software is installed.

Cheers

My system specs:

MacBook Pro (15-inch, Early 2011), 2,2 GHz Intel Core i7, 16 GB 1333 MHz DDR3, 256 Crucial SSD

I recently installed a new modem to achieve increase speeds from Cox Ultimate service (i.e. 300 mbps down and 30 up). As a result, I frequently check all my equipment to ensure these speeds were coming in. After a couple days, I noticed my 5K iMac would sometimes slow down to speeds 1/3 of what it should be. I also realize by simply turning off the wifi and then back on, the speeds would restore. I haven't tried any of the fixed yet documented in this thread. I am a bit bummed.

This seems to have helped me out too. Thanks very much jubamad! 🙂

Even after going all the way up to Mac OS 10.11.2 El Capitan, I spent a half day trouble shooting wifi connectivity issue. I finally powered up my old laptop and realized the wifi network was up and running well just not with Mac OS 10.11.2 El Capitan. I found an excellent youtube video on how to fix the issue. Worked for me. video at youtube https://www.youtube.com/watch?v=-eCxgPiTb5s

I've been there and done that (video recommendations)... my network remained slow, and in fact has been far worse since Apple published its update. I wish I could do the system reinstall, but that requires a network connection, and Apple's notwork won't support the installation requirement.

I find the WiFi fiasco as worse than Windows' Vista ... a watershed moment when I finally discarded Windows. IOS launches have been nearly as destructive. Cook does not seem to get it: people have choices. As I see it, Apple is probably not far from collapsing in a manner not unfamiliar to us: the collapse of Microsoft.

Is it the same even though you're close to your router? I had the same problem when I was connected to my 5Ghz band and being a bit far from the router. But when I started using a repeater/extender to get a stronger signal closer to me, I never got the problem again. Like I mentioned in my earlier post, there must be something wrong with the OS that makes the download speed slower when the wifi signal is not the strongest.

* I never had the problem when connected to 2.4Ghz band.

** My repeater extends my 5Ghz to 5Ghz band.

Even after going all the way up to Mac OS 10.11.2 El Capitan, I spent a half day trouble shooting wifi connectivity issue. I finally powered up my old laptop and realized the wifi network was up and running well just not with Mac OS 10.11.2 El Capitan. I found an excellent youtube video on how to fix the issue. Worked for me. video at youtube https://www.youtube.com/watch?v=-eCxgPiTb5s

Actually, after some success it turned out that my wi-fi problem was not fixed by a tech. It did return. 😠

However, after updating to the latest OS X release, 10.11.2, the problem went away. There were reports of a wi-fi fix and it seems that was true. Happy with my 12" MacBook now. 🙂

I was struggling with slow wifi since El Capitan update (honestly, it can be that this was the case already before that update! Cannot really say for sure!). I was extremely happy to see that last OSx update was including fix for Wifi issue finally, unfortunately that was NOT the case with my mac!

It seems that now I FINALLY found solution and wanted to share it with you all, hopefully it can help someone else.

First, some details of my setup:

I use MacBook Pro (Retina, 13-inch, Early 2015) with El Capitan 10.11.2

Wifi router is Buffalo Air station 125, 2.4GHz, i use AES encryption with PKI.

I have docking station and two external displays connected via thunderbolt adapters plus magic mouse.

Symptoms:

Wifi was very very very slow, like 0,7Mbps (mainly I used speedtest.net for testing). Using iPhone with same router showed correct speeds, so issue seem to be only in my mac. In some point I noticed that if I take my mac out from docking station and use it with out external displays, connection speed will be back to normal.

What I have tried?

I browsed a lot information via google and it seems that there is lot of same kind of issues with solutions (deleting settings, manually configuring DNS & MTU settings etc...), none of those fixes where helpful for me, absolutely no difference at all.

If found one discussion where someone have had some help by disabling bluetooth. For me this was not fixing anything, but also noticed that bluetooth frequency can be around 2,4Ghz, same as my wifi router uses. This lead me to try out something what finally was solution.

Solution

Simply, I logged into my wifi router setup and changed channel from Auto (it showed channel 11 at that time) to 1. After reboot my Wifi router, speed was back to normal!

The recent update which allegedly included a wifi fix did nothing for me, in fact the problem seemed to get worse. My internet will become unusable every 5-10 minutes and I need to turn wifi off and on (on the mac) and it instantly re-connects.

I have tried a few fixes thus far (DNS and proxy settings, resetting PRAM, deleting the saved wifi network and re-adding it, and of course a million reboots of the router and machine at first, before I realized this was a problem with the **** OS) .

I couldn't access my router settings via wifi so I will try jsaa29882's suggestion later after I bring home an ethernet cable.

I just bought the machine in September... I've always been a PC user and this was my first Mac purchase. Ha. Feels like the joke's on me now that I see that some people had this problem throughout Yosemite's life span? Ridiculous. I didn't even realize such glaringly defective products were possible from such a giant?!

Hi everyone – just wanna share. I’ve had the same issue/problem for the longest time with my El Capitan. I had to use my Windows laptop for Wifi connectivity. However, the recent update really fixed this issue. I found it really fast. Hopefully this is true to everyone.

Cheers,
Giusseppe

Spent a lot of time yesterday with an Apple Tech Supervisor ... and in a 3-way call with my internet provider, Comcast. The solution was Comcast updating the firmware in the modem/router they provide. Rebooting one's router does not mean updating firmware. In my case, the router was no longer fully compatible with El Capitan. Those who own their own routers may have to chase down a firmware upgrade. This is not my guess, but the opinion of the Apple tech ... and whether it involved a huge firmware update or simply a reconfiguration, the ROUTER was my problem. Smarter guys than me on this forum can fine tune my findings.

I had the problem with Yosemite, tried some of the various fixes, nothing worked. Apple tech help said I needed to use Capitan. Upgraded. Problem worse than ever. Using new Air is incredibly frustrating, have to turn off/on wifi to print to wireless printer, to send email, etc. Does Apple care about this problem?

johnettpdx wrote:

I had the problem with Yosemite, tried some of the various fixes, nothing worked. Apple tech help said I needed to use Capitan. Upgraded. Problem worse than ever. Using new Air is incredibly frustrating, have to turn off/on wifi to print to wireless printer, to send email, etc. Does Apple care about this problem?

Changing the wireless chanel, updating router firmware... all to no avail?

Did you do a clean install or just updated from Yosemite?

I'm the author of several books, have written for major publications, and I am wondering if I should be required to have a degree in computer science in order to use my Airbook? I don't know much of what you are speaking of here, and I'm not sure I should be required to repair/fix a machine that should be working. In the 1980's an article was done on how I installed Macs into a newspaper business, so I've been loyal to Apple for a long time. I think the expectation that the machine work, without my knowing how to do something with "firmware" isn't unreasonable.