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.
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.