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robo44

macrumors member
Original poster
Feb 1, 2013
59
0
I keep having strange things happening on my iMacs wifi.
I went over to fibre and my speed should be 40mg & 9mg and get this for a while until it drops to 8 & 7 ?
Now I've googled it and messed around with with mac settings with no joy.
Ive opened up the router and changed channels and sometimes the speed increases to what it should be but eventually drops back to the slower speed and stays there until i mess with the channels again.
Any ideas anyone ?
 

Dreadnought

macrumors 68020
Jul 22, 2002
2,060
15
Almere, The Netherlands
Could be interference from neighbours wifi or even a dect phone, baby monitor or (3rd party) wireless mouse and keyboard. First try an ethernet cable to see if speeds it stays stable and fast. If it still slow, then it's probably not the wifi, but the connection. Also set all settings to "auto", especially for the channel and if you can set up a 5 Ghz connection, give that a try.
 

robo44

macrumors member
Original poster
Feb 1, 2013
59
0
Could be interference from neighbours wifi or even a dect phone, baby monitor or (3rd party) wireless mouse and keyboard. First try an ethernet cable to see if speeds it stays stable and fast. If it still slow, then it's probably not the wifi, but the connection. Also set all settings to "auto", especially for the channel and if you can set up a 5 Ghz connection, give that a try.

This is where it gets even stranger, the speed has just dropped again but if i do a speed test on my iPhone i get the faster speed so it has to be the mac doesn't it ?
 

antman2x2

macrumors 6502a
Mar 1, 2011
528
198
New YAWK
Is hardwiring an option for you?

I recently ran into almost the exact same problems as you however I would also experience frequent disconnects.

I tried everything, all the software tweaks, the hardware tweaks, I even tried different routers.

Finally I got fed up enough and hardwired everything.

Everything is now blazing fast and 110% stable. Seriously if hardwiring is an option than consider it.
 

robo44

macrumors member
Original poster
Feb 1, 2013
59
0
Is hardwiring an option for you?

I recently ran into almost the exact same problems as you however I would also experience frequent disconnects.

I tried everything, all the software tweaks, the hardware tweaks, I even tried different routers.

Finally I got fed up enough and hardwired everything.

Everything is now blazing fast and 110% stable. Seriously if hardwiring is an option than consider it.

Its in another room and where the mac is now there isn't a phone socket.
Ive just ran another test and the mac is slow as usual but the iPhone is full speed and so is my sons pc!
There must be a setting as it is now 100% a mac problem..
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
It could be the location of the iMac compared to the base station - is there anything between them that could interfere with the signal?

Microwave, TV, cordless phone, or really thick walls or a water tank, or chicken wire/mesh screening? Draw an imaginary straight line between the iMac and the router in your house and think about all of the things between them on that direct line.

If this is a hardware problem it could be that one of your wifi antennas in the iMac are disconnected. Can you move the iMac to another room to test if the connectivity improves?

If you can move it so that you can hardwire it with an ethernet connection just for testing you can start ruling things out.
 

blueroom

macrumors 603
Feb 15, 2009
6,381
26
Toronto, Canada
As mentioned make an effort to hardwire it. Even Ethernet over Power adapters can be used (much slower than GigE) but generally more reliable than WiFi.
 

robo44

macrumors member
Original poster
Feb 1, 2013
59
0
As mentioned make an effort to hardwire it. Even Ethernet over Power adapters can be used (much slower than GigE) but generally more reliable than WiFi.

Right i hardwired it and all running perfectly but there is no way i can hardwire it all the time as i already run 2 STBs straight into the Sky Hub :confused:
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
Right i hardwired it and all running perfectly but there is no way i can hardwire it all the time as i already run 2 STBs straight into the Sky Hub :confused:

So this looks like a wifi interference issue *or* a hardware problem with the iMac (one or more antennas disconnected or damaged).

Try using the iMac in a different room in the house - preferably much different to where it is when it's having problems - for example, have it where your son's PC is and see if the wifi is good there (since you say his PC always has good speeds). If the wifi is still terrible then it's likely something you should have Apple look at.
 

robo44

macrumors member
Original poster
Feb 1, 2013
59
0
So this looks like a wifi interference issue *or* a hardware problem with the iMac (one or more antennas disconnected or damaged).

Try using the iMac in a different room in the house - preferably much different to where it is when it's having problems - for example, have it where your son's PC is and see if the wifi is good there (since you say his PC always has good speeds). If the wifi is still terrible then it's likely something you should have Apple look at.

Right i think i may of sorted the problem. Sky gave out some wifi boosters a while ago and i had it upstairs just to give a better signal if i was using my iPhone in bed. So i brought the booster downstairs and set it up next to the iMac and all seems ok so far fingers crossed..
 

johnnnw

macrumors 65816
Feb 7, 2013
1,214
21
When the speeds drop down to 8 and 7, hold option and click the wifi symbol at the top.

Check your transmit rate and see if that is changing at the same time your speeds are dropping
 

blueroom

macrumors 603
Feb 15, 2009
6,381
26
Toronto, Canada
No i mean i can't move the router nearer to the mac as i have it hard wired in the lounge and can't move it.

Then either run a long Ethernet cable or look at Ethernet over Power adapters.

OR

Get a decent WiFi router and put your ISP router (usually crap) in gateway mode.
 

MacCult62

macrumors newbie
Dec 8, 2012
8
0
Montreal
Slow WiFi on iMac

I have the same problem (slow WiFi) on my iMac (late 2010; OS 10.9.4) for the past couple of months. My MBP runs at 10.5 Mbps, while my iMac crawls at 1.6 Mbps from the same location. I connected the iMac to the router, and speed goes up to 10.5 Mbps. So I figured it was a problem with iMac.
I erased all widgets in the Dashboard; I removed a lot of login items; freed about 150 GB on the hard drive. All to no avail. I removed my WiFi network and then added it again. Download speed went up to 6.8 Mbps, but a few minutes later it was back to 1.6 Mbps.
When I run Disk Utility, it cannot find a problem with the hard drive. Same thing when I run a Network diagnostics; all seems A-1 OK.
Any clues or tips before I reformat the hard drive and reinstall OS X?
 
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