My last post on things I’m learning during this transition to a new computer buried some interesting ideas in a long-winded story: Update on New MacBook Pro.
Here’s my executive summary on external storage, and ways to connect it to a modern Macintosh.
External storage speeds and interfaces
When I ordered the new MacBook Pro I ordered a Thunderbolt to Firewire Adaptor because I have Firewire 800 external hard disks and new Macs support Thunderbolt and USB 3. In order to use my old external drives with firewire I needed an adaptor. Two of my drives also have USB 3 but I bought the firewire adaptor because I had no experience with USB 3 and my experience with USB 2 has been less than wonderful. This “baggage” about USB has now changed (read on).
I’ve also been shopping for some new drives and wasn’t sure what to get. In doing my research here’s what I’ve learned.
1. Thunderbolt is faster than USB 3 which is faster than Firewire 800 which is faster than USB 2.
2. Thunderbolt and Firewire 800 are daisychainable at the device: an external hard disk/SSD could have two ports (or not) for a pass through connection to another device. USB 2 and 3 are not although multiple drives can be connected to a USB (3) hub. And there are Thunderbolt hubs as well so one might have multiple single-port Thunderbolt drives connected to a hub.
For a MacBook Pro user the pass-through/hub thing is a non issue: the machine has two Thunderbolt ports and two USB 3 ports so one could have multiple single-port external storage devices connected simultaneously.
3. External storage might be a hard disk spinning at 5400 RPM, a hard disk spinning at 7200 RPM or an SSD (solid state drive). There is a significant speed difference between 5400 and 7200 RPM but an even bigger one with SSD which is extremely fast.
When you put all of this together you end up with some general ideas:
1. If you have a 5400 RPM external hard disk, Thunderbolt isn’t any faster than Firewire or USB 3, the limiting factor is the speed of the hard disk which is slow relative to the connection speed.
2. If you have a 7200 RPM hard disk Thunderbolt doesn’t get you any more speed than USB 3 or Firewire but USB 3 is faster than Firewire so if you don’t need to use Thunderbolt for some other reason, its is probably overkill and USB 3 is the thing to use on modern Macs.
The bottom line is that Thunderbolt, while very fast, is probably overkill for most spinning hard disks and if you don’t need some other aspect of Thunderbolt, USB 3 is fast enough and a lot cheaper and more widespread in use in external enclosures.
3. If you have an SSD in an external enclosure Thunderbolt will give you the fastest throughput although USB 3 is close enough so that the extra expense and rarity of a Thunderbolt interface may or may not be worth it. And, buying a 500GB or 1TB SSD is a lot of money. At this point, spinning hard disks are still the way to go for backup or large storage needs until the cost of flash memory comes down more. It will, just not quite yet.
Thunderbolt, USB 3, and Firewire 800 can boot a Macintosh so if you’re making SuperDuper backups that you’d like to be able to boot your computer from in an emergency, any of them will do (provided the external drive controller can do it). Again, the limiting factor on performance will be what’s inside the enclosure: spinning hard disk of one speed or another or SSD.
What I’m doing
I have a 1TB SSD in my new MacBook Pro and I like to have two SuperDuper backups in rotation and one Time Machine backup so for this I’ll need two 1TB drives for SuperDuper and one 1TB or 2TB drive for Time Machine.
I’ve got a number of 500GB and a few 1TB Firewire hard disks (some running at 5400 RPM) and I’m going to start slowly replacing them, mostly with external hard disks running at 7200 RPM with USB 3. Here’s the first one I bought:
I have to say, it’s a great external drive: solidly built, fast, with all cables included. I’m using it for Time Machine and I used the Thunderbolt interface for the initial (2 hour) backup but now I’m using USB 3 for daily backups and it’s extremely fast. I think I could have probably gotten by with this drive which is the same thing minus the Thunderbolt:
The latter drive will be the next one I get although I’m in no rush now because I’m using my older LaCie Rugged drives with USB 3 and they’re working fine.
I bought an inexpensive USB 3 enclosure for the SSD that was in my old, dead MacBook Pro and it’s working very well:
I just had to take some brackets off the SSD for it to fit in and once off, it snapped in in a few seconds. It’s now in my SuperDuper rotation and at 500GB, I’ll keep it in rotation until I outgrow it.
The bottom line is that USB 3 seems to be fine for everything I’m using it for. At this point I’ve not attempted to boot and use my new computer from any of the external drives although I plan to do a test with the external SSD later today. I’m quite sure it will be fine. I’m hoping that by the time I need to replace it with a bigger capacity SSD the prices of 1TB SSDs will come down and that’s what I’ll get.
The new MacBook Pro is wonderful: extremely fast to boot and shut down, extremely fast launching applications, extremely fast moving around in Lightroom (where my older machine was showing signs of age) and the retina screen is easy on the eyes with very little (if any) reflection.
The only bumps in moving from old machine to new were the limitations of Apple’s Migration Assistant and my incorrect understanding of what was needed to migrate and the speed and interfaces on my hard disks.
Hopefully these notes will be useful for anyone about to go through something similar. I can’t emphasize this enough: if you’re not backing up your computer you need to get on that, today. If you are backing it up, make sure your backups are working and doing what you want them to do. In other words, test them from time to time.