Reader Frank Blank has drawn a blank in regard to upgrading the wireless connection on an older iMac. He writes:
I have three Macs networked at home through an Airport Extreme Base Station. The MacBook and Intel iMac communicate like greased lightning. Communication with the 2.1GHz iMac G5 is much much slower. Since the laptop, Intel iMac, and AirPort Base Station utilize 802.11n, and the iMac G5 uses 802.11g, is there a way to upgrade the older iMac to the faster wireless speed?
The least expensive way to do this is to eschew wireless on the old iMac and run an Ethernet cable from the Base Station to the iMac. Your iMac’s network performance will increase dramatically and its “g” wireless won’t slow down the rest of the wireless network.
On the other hand, perhaps you don’t feel like completely rearranging your home so that the Base Station and iMac sit near each other. If not, you can upgrade the iMac to 802.11n, but not internally. Apple’s n-flavored wireless cards don’t work with older iMacs.
You can, however, add 802.11n via USB. For example, Other World Computing sells the MaxPower 802.11n/g/b Wireless USB 2.0 Stick Adapter for $50. Jack it into a USB 2.0 port, install the driver, choose it as the wireless adapter you’d like to use, and your older iMac is communicating at 802.11n speeds.