USB3 WiFi interference

I have been using the new iMac Retina for a week and have encountered serious problems with WiFi connections, including repeated failures of wireless keyboard and mouse to establish connections. I know that others have been having the same problem and from what's on the Web it's clear that it is not confined to the iMac, or to other Apple computers, or to a particular operating system. I am using Yosemite for which Apple have just issued an update that is supposed to at least mitigate the problem. It does not. And the reason is that it is a hardware problem that affects all USB equipped devices - computers and external devices alike. In brief, USB 3 interferes with WiFi to such an extent that they can scarcely be used together.

The problem has been known for at least 2 years. There was an Intel White Paper about it dated April 2012:
USB 3.0* Radio Frequency Interference on 2.4 GHz Devices

And another published inPC Mag more recently:
Networking Reviews, Ratings & Comparisons: Wireless Witch: The Truth About USB 3.0 and Wi-Fi Interference

Intel suggest that the situation can be mitigated by wrapping all USB 3 peripherals in Aluminum foil!. Unfortunately,even that does not solve the problem because, even with no peripherals attached, the USB 3 ports themselves cause interference.

The USB 3 protocol should clearly never have been approved, at least until the problem could be genuinely mitigated. As it is,for the new iMac Retina and its users, this is an unmitigated disaster.

Hello & welcome to the forum!

Thanks for those links - interesting reading - I've not noticed a problem w/ my iMac (spring 2013 model) & AirPort Extreme dual band router (previous flat model) but I do not have anything attached to the USB port of the device.

So, just curious what router you may be using and whether it has a USB 3.0 port? Is there a printer or HD attached as a potential source of Wi-Fi interference in the 2.4 GHz band? What have you tried to alleviate the problem w/ your KB & mouse, which of course are Bluetooth connected using that same band frequency? Might help others to better appreciate similar issues w/ their wireless equipment. Dave

My router is a DrayTek Vigor2130. It does not have a USB 3 port. I have a home lan but it is entirely Ethernet connected and I do not use WiFi normally. The problem for me is with the Bluetooth connection to the wireless keyboard and mouse on the iMac, but that is the same problem as with WiFi generally. (I don't have the problem with another Mac that does not have USB 3, only USB 2. There are a couple of USB 3 external HDDs attached to that computer, but that does not seem to cause interference with its wireless keyboard and mouse. The iMac has some USB 3 devices attached (external HDD, DVD player and sound bar). But even with them removed, the problem persists, presumably because the USB 3 ports are themselves causing interference.

I have had a long talk with an Apple techi about it and they are looking into it. But I find it difficult to believe that Apple and USB 3 device manufacturers were unaware of it as it has been known about for more than 2 years.Apple may come and collect the iMac and try and resolve it. But if the problem is as Intel describes, I can't see what they can do about it short of ripping out the USB 3 bus and putting in something that does not kill WiFi. I suppose it might be mitigated by using shielded cables with boots (metal ones) at both ends,rather like certain Ethernet cables.

Meanwhile, I shall use a wired keyboard and mouse. But that is not a solution for people who use WiFi for regular communication. As I said, it is an unmitigated disaster for which those who allowed USB 3 to use the same waveband as WiFi and those (including Apple) who implemented it on their machines. regardless are to blame.

Buy a dual band router = 2.4 GHZ and 5 GHZ. Use the 5 GHZ band to eliminate any possible interference. Most modern routers sold nowadays are dual band anyway including Apple routers. Also I don't believe this is as big a problem as stated. It's long been known that there are many things which interfere with the 2.4 GHZ band including baby monitors, remote telephones, etc. And by the way, I have three USB 3.0 ports on my iMac and have not experienced any interference with my WiFi signal or blue tooth.

What caused most interference to my system was a Uniden Hands Free phone unit. By purchasing a TP-LINK dual band router and opting to use 5GHz band only, interference is completely avoided, and I swear connection and speed is even a little faster.

The problem is specific to the iMac running Yosemite (including latest update). This machine is not in the same room as the router. The machine in that room is a PC that does not have the problem. Nor do an iPad or Mac and Windows laptops used elsewhere in the house at some distance from the router.

Apple are aware that there is a problem, and there are posts about it all over the Web. Some think it is due to Yosemite, including Apple (hence the upgrade). My university has issued the following about it:

"It has been widely discussed on Mac user forums that there are issues with the Wi-Fi connectivity in the latest version of Mac OS X.

IT have seen reports already of issues with this update on staff and student machines. We do not recommend that you update to this version of Mac OS until an update has been released by Apple. There will be problems with accessing University resources such as Wi-Fi until this has been fixed.

An example set of symptoms of this fault include:
Your network works fine for a while, typically between about 30 seconds and five minutes, and then fairly abruptly begins to suffer almost total traffic loss. While this happens, your network connection appears to be active, yet typically, you cannot connect to anything.

While we do not have a workaround, we will update this information as soon as possible."

Others think it is a problem with USB 3 on the iMac or with the iMac itself. In any case is still a problem, and not only for WiFi but also Bluetooth, which makes it is virtually impossible to use the wireless keyboard supplied with the iMac. Because the iMac is both a computer and monitor, it is not possible to use the keyboard or mouse at any distance from it. I can get round that problem by using a wired keyboard, as I do not use WiFi from this machine. Those who do, have no such workround.

Apple have offered to collect the machine and test it in their lab, but they can hardly do that with every machine they have sold.

I think this issue ought to betaken more seriously than it has been so far.

SO, what to do w/ Yosemite? I've upgraded my MBPro w/ USB 3.0 ports to 10.10.1, which uses a Wi-Fi connection from my AirPort Extreme in the next room - I've not noticed a problem yet. My wife uses our iMac (spring '13) w/ USB 3.0 ports which is next to the router but cabled w/ the Wi-Fi off; she is still on Mavericks - her Apple KB & mouse work fine @ the moment - should I upgrade that machine or wait for Apple to release the next Yosemite update? I'm sure there are many w/ the same thoughts. Dave

Just to add a wrinkle. An iPad that connects to WiFi in a room adjacent to the one with the iMac refuses to do so when in the same room. But that is when the iMac is up and running, not when it is turned off. That could mean the problem is with Yosemite, or it could meant that it occurs whenever there is power to the USB 3 ports. If it is Yosemite, Apple should be able to fix it fairly quickly, but it it is a the iMac itself or its USB 3 ports that's a different story. Will they have to call them all in like car makers when some serious fault is detected? Or will they just ignore it?

And something more. I have also been thinking of getting a USB 3 hub and that's another story, too. They are having the same problem as wireless keyboards and mice,which clearly implicates usb 3 itself. There is extensive discussion of the problem on a Forum here:
https://discussions.apple.com/thread/4577942?tstart=0

It makes depressing reading. I am beginning to regret having got the iMac Retina as the only ports other than USB 3 are Thunderbolt for which there are few available devices and those inordinately expensive. Thanks, Apple!

I haven't seen the problem here and I'm using a late 2013 27" iMac with USB 3 ports which are in use every day. No interruption of WiFi or bluetooth. And I'm running Yosemite 10.10.1.

Like I mentioned earlier, if it's a problem with interference from 2.4 GHZ signals being generated by the USB 3 ports, that can be eliminated since most modern routers are now dual band. Also, since Apple computers fully comply with US FCC standards, I can't see how something like that could slip by. I suspect the problem is with Yosemite. Supposedly, 10.10.1 fixed WiFi problems and it appears Apple is preparing 10.10.2 in beta right now.

Changing the waveband of the router will not solve the Bluetooth problem. And buying a new router and still having the problem doesn't seem a sensible thing to do.

If you are not having these problems when so many others are, you must have some solution that others do not. Can you let us know what it is?

silvermac said:

just to add a wrinkle. An ipad that connects to wifi in a room adjacent to the one with the imac refuses to do so when in the same room. But that is when the imac is up and running, not when it is turned off. That could mean the problem is with yosemite, or it could meant that it occurs whenever there is power to the usb 3 ports. If it is yosemite, apple should be able to fix it fairly quickly, but it it is a the imac itself or its usb 3 ports that's a different story. Will they have to call them all in like car makers when some serious fault is detected? Or will they just ignore it?

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Well, I'd have to agree w/ Chscag - my previous post below duplicates his experience, i.e. no interference near the iMac which is still on Mavericks, but if the issue is interference of the router's Wi-Fi signal w/ USB 3.0 ports, then not sure the OS X installed makes much a difference?

Concerning iPad usage (as discussed in the quote above), I use my iPad 2 all of the time next to my MBPro (spring 2013 model w/ USB 3.0 ports) in the den - no problems at all; and my wife uses her iPad Mini routinely next to her iMac; and I just took my iPad into our computer room next to the iMac - worked fine.

I can offer no solutions except that we are not experiencing the issues described @ the moment - Dave

raddave said:

so, what to do w/ yosemite? I've upgraded my mbpro w/ usb 3.0 ports to 10.10.1, which uses a wi-fi connection from my airport extreme in the next room - i've not noticed a problem yet. My wife uses our imac (spring '13) w/ usb 3.0 ports which is next to the router but cabled w/ the wi-fi off; she is still on mavericks - her apple kb & mouse work fine @ the moment - should i upgrade that machine or wait for apple to release the next yosemite update? I'm sure there are many w/ the same thoughts. Dave

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If you are not having these problems when so many others are, you must have some solution that others do not. Can you let us know what it is?

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Like Dave stated above, I can offer no solution because I have not experienced the problem. Not saying that there isn't a problem, but it does seem strange that more of our members have not reported it. The first I've heard of it is from you.

And since so many computers are now equipped with USB 3 (PCs and Macs) why haven't we heard more about this from the Windows folks? And don't tell me Windows machines are built better than Macs. Routers and Blue Tooth are utilized with Windows machines the same way as they are with Macs.