mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
I don't know if this is an issue with software, hardware or the router but I am having quite a few issues with my 13" tbMBP from last year.

The wifi is super slow quite often and will occasionally disconnect completely.

1. If I leave it to reconnect on its own when its disconnected it can take ages to reconnect but if I turn the wifi off and on again it will usually reconnect almost instantly.

2. The wifi slows to an utter crawl at times. We are taking 1.5mb down instead of 60mb. If I turn the wifi off and on again it will suddenly come back up to speed for a while before eventually getting sluggish again.

I have tried all the software fixes I can find online like deleting networks, plist files etc and nothing works for any amount of time.

I have a google wifi router if that makes any difference.

My macbook is coming up to the end of its warranty so if it could be a hardware issue I would like to get it seen to before that.

Any ideas or has anyone else had this issue before?
 

Jimios

macrumors member
Nov 7, 2015
47
31
For starters, do any other devices on the same wifi experience the same problem, or just the MBP?
 

mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
Just seems to be the MBP. I have an iPhone 7+ sitting next to the macbook and the wifi is much better on that.

I've just run a speedtest on my MBP and iPhone

iPhone
33.53 down
11.15 up
9ms ping

MBP
1.82 down
3.36 up
44ms ping
 

Jimios

macrumors member
Nov 7, 2015
47
31
I would personally try to find (or borrow from a friend) another router, or another laptop, and make a few tests to see if the problem persists. I can't think of a software recommendation for this issue.
I've had issues with wifi like the one you describe, but I found out it was the router. Switching wifi on/off on the router itself would fix it for a few days.
 

mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
Ive just tried with my GFs Macbook Air and an iPad and both of them are absolutely fine
 

mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
So i've figured out what the issue is.

Basically the two LG ultrafine 4k monitors that the MBP is sat under are generating interference. If I move the laptop to the front of the monitors and about a foot to the side of them everything is fine.

Suddenly I'm on 5ghz instead of 2.4ghz and im back up to full speed.

I know the 5k had issues with shielding but I thought that was when the monitor was right next to a router and I can't seem to find any issues with wifi interference. Anyone had any problems with monitors interfering with wifi?
 

Fishrrman

macrumors Core
Feb 20, 2009
22,178
8,227
Do you have stuff plugged into the USB-c ports (running external displays I would assume that you do)?
If so, there's the possibility that the USB3 cabling is generating interference to the wifi signals.

If 5ghz works for you (and 2.4ghz does not) -- I'd just go with "what works"...
 

mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
Do you have stuff plugged into the USB-c ports (running external displays I would assume that you do)?
If so, there's the possibility that the USB3 cabling is generating interference to the wifi signals.

If 5ghz works for you (and 2.4ghz does not) -- I'd just go with "what works"...

I would love to do that but unfortunately I have the google wifi router which seems brilliant until you have an issue that requires you to actually change anything. It broadcasts on a single SSID with both bands and you cannot pin a device to a particular band, you can't turn off 2.4ghz and you can't separate them into 2 SSIDs so the macbook just connects to whichever it thinks is better.

I do wonder if its the interference from the USBC as some people suggested the cables on the ultrafines were the source of the interference but apparently it was only the thunderbolt 3 cables with the 5K that had that issue.
 

newellj

macrumors 604
Oct 15, 2014
7,763
2,647
East of Eden
Ive just tried with my GFs Macbook Air and an iPad and both of them are absolutely fine

I did some research on this about a month ago. I don't remember the specifics, but IIRC this is an issue that is attributable to the rMBP itself when you have certain USB-C devices attached. I also seem to remember that this issue happened on 2.4gHz but no 5gHz. Can you change your connection?
 

Jimios

macrumors member
Nov 7, 2015
47
31
Apparently there is an issue with 2.4GHz WiFi when specific USB-C accessories are connected.
You can read more about it here and here.
 

mctrials23

macrumors 6502a
Original poster
Sep 19, 2013
507
501
Cheers for the replies guys, really appreciate it.

Its coming up to the end of its one year warranty so I am thinking about taking it to the apple store to have them look at it. I'm just not convinced I will get anywhere. Its not the easiest of problems to recreate properly.

Trying to explain that the 2.4ghz wifi is awful when usbc devices are connected isn't easy to reproduce. Any ideas? At the moment I just have 2 LG 4K ultrafines connected so its not like its interference from some ****** £10 dongle.

Its quite literally night and day between 2.4ghz and 5ghz as well. I thought 2.4ghz was supposed to be better when there is interference or lots of walls between you and the router. I know its not as quick as 5ghz but the difference in speed is clear from the speed test above and that is a poor representation of how bad the internet and file transfer is on 2.4ghz.

The connection is so patchy and up and down between just about useable to nothing works.
 

adonis3k

macrumors 6502
Apr 15, 2012
473
66
Ive just got a 2017 MBP and was using an external SSD via USB-C to do my Time machine backup and my Wifi was not connecting. I swapped the cable over to another USB-C one and now its connecting fine.

Bloody annoying, also a USB-C dongle I bought is not connecting either and keep getting a "USB has been disabled" BS! Should of kept my older 2015 MBP!
 
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