I’ve been using a Mac Pro for many years but it’s time to upgrade my computer. I’m not ready for the investment that comes with a new Mac Pro so I’ve settled on a 27in iMac. The problem is that I want to use the four hard drives that are in my current Mac (set up as four separate volumes) with the new iMac. What do you suggest?
If I were in this position I’d strongly consider a 4-bay drive enclosure. This allows you to plant all your drives in a single box and connect them to your iMac with just one cable. The question you must next consider is “what kind of cable?”
Today’s iMacs have both USB 3.0 and Thunderbolt ports, and enclosures are built with each kind of connection in mind. As far as you’re concerned the difference comes down to price and – depending on how you configure the drives – speed. For example, at Other World Computing you could purchase an empty ThunderBay IV 4-bay Thunderbolt enclosure for US$439. For just US$269 you could have the company’s 4-bay Elite Pro Qx2 enclosure, which supports eSATA, FireWire 800 and USB 3.0.
Now, let’s talk about configuration. If you want to use those drives as you currently are, you’ll configure them in a JBOD (Just a Bunch Of Disks) arrangement, where each disk operates as a separate volume. In this kind of configuration USB 3.0 is fast enough. As explained by Jim Galbraith, you’re not going to see a vast speed difference between USB 3.0 and Thunderbolt with a 7200 RPM hard drive as the drive isn’t fast enough to take advantage of Thunderbolt’s greater throughput. (The same can not be said for solid state drives, however.)
That said, Jim did tell me that if you configure those four drives in a striped RAID array, USB 3.0 could prove to be a bottleneck. In that case you’ll want to go with Thunderbolt instead.