Q I have ordered a new iMac 27” and need to work out the best way of connecting my external hard disks to it; these include a clutch of LaCie drives accessed via FireWire 800. Which would be better: eSATA to Thunderbolt, FireWire to USB 3, or what?

A Of the interfaces on your new iMac, by far the best performing is Thunderbolt.

In theory you would be best purchasing an external Thunderbolt 4-slot expansion chassis, and populating it with the most recent drives from your current system. There are two snags: unpopulated Thunderbolt chassis are hard to come by but populated ones expensive; moreover your current drives may not run reliably for much longer.

Unless they are Enterprise specification, modern hard disks have only 3 year warranties, and are increasingly likely to fail once older than 3 years. So any drive older than 2 years is probably going to give you less than two years of reliable service.

A £25 FireWire to Thunderbolt adaptor might be a good stopgap, but uses very little of Thunderbolt’s performance potential. It should though give you the time to progressively upgrade your external drives to get the best out of them.

Updated from the original, which was first published in MacUser volume 29 issue 05, 2013.