I'm backing up two iMac's (with Time Machine) into one single 500GB USB external HD. The one machine that has the external HD plug into via USB performs the backup at a reasonable amount of time (no problem here). But the second machine, which connects to the extrenal HD via Airport (through a D-link router) performs the backup at a painfully slow rate. I know this is not an ideal setup, but I was wondering what can be done to improve here (short of buying a second drive). Maybe if I connect the second machine to the network (router) with a ethernet cable, instead of it being wireless now? Maybe some tweaking of the network/filesharing system preferences? Or am I doomed with this setup and most definitely must look into purchasing a second drive? TIA BTW - On one machine I only have in use about 100GB of a 320 GB disk and it performed an initial backup in only a few minutes. On the second machine I use about 120 GB of a 160GB disk and so far about 4 hours have gone by and only 51.5GB have been backed up.