Home Tech LaCie Thunderbolt SSD boot drive for blistering performance

LaCie Thunderbolt SSD boot drive for blistering performance


if you like this article please see my follow-up in August 2012: The cheaper option

Last May I bought a new 27in iMac as soon as it was announced. Because of my positive experience with solid-state drives (on two MacBook Airs and a MacBook Pro) I ticked the box for the expensive dual-disk option, including a 256GB SSD boot drive. When I discovered there would be a six-week delay, I decided to delete the SSD and, instead, go for the 7,200 rpm 1TB hard disk. To ensure speed I chose the fastest i7, the 3.4GHz, processor and 8 GB of RAM.

Big mistake

It was a big mistake to delete the SSD. I should have waited. For the past ten months the iMac has been nothing but frustration when compared with my lowly late-2010 11in MacBook Air. Disk access speeds are abysmal (in comparison) and starting or restarting from sleep takes far too long. 

I investigated the options for retro-fitting an SSD alongside the standard 1TB. As we all know, Apple will not do this, but I found a couple of companies that said they could. There is also the iFixit kit which was highlighted a couple of weeks ago, but a DIY jobs is well outside my modest capabilities. Having watched two Asian enthusiasts wresting with an iMac in the above YouTube clip, I was more than ever convinced this is not for me. 

Partly out of inertia and largely because I didn’t want to lose the iMac for even a week, I did nothing.

Alternative strategy

I started to look for an alternative solution and eventually hit on LaCie’s pricey but well-received Little Big Disk external Thunderbolt SSD. I reasoned that the speed of the Thunderbolt connection could make the LaCie into a viable boot drive.

It is received wisdom that an external drive should never be used as a boot drive except in emergency. In the days of mechanical drives and USB connections, this was undoubtedly prudent advice. But Thunderbolt and SSDs have changed all that. It is now a viable option.

After rummaging around other users’ experiences I became convinced it would be a feasible option. It isn’t a cheap one, though, because the 240GB LaCie (which actually consists of two striped 120GB drives in a neat casing) sells in the Apple Store for £699. I did check around but couldn’t find it anywhere else, let alone cheaper. We’re at the (cash) bleeding edge of technology here, I am afraid. Next year it will be a different story.

Phenomenal improvements

Yesterday I bit the bullet and bought the drive (plus one of Apple’s expensive £39 Thunderbolt cables). Installing the Little Big Disk and making it into the default boot drive took a couple of hours and was super easy. I will cover the details later.

The results are absolutely phenomenal. My once lethargic iMac has been totally transformed. It boots quicker than the MacBook Air, wakes from sleep within a couple of seconds. Programs launch with only one icon bounce, when ten was the previous norm. In short, it is fast.

Read at 490 Mbps

The statistics are nothing short of astounding. Before adding the LaCie, the iMac’s 7,200 rpm drive was recording slothful read/write speeds of 48 and 49 Mbps. After installing the Lacie these speeds have increased to 490/253 Mbps. Actually, the 490 is right off the scale at the end of the red zone on the BlackMagic disk speed test. The real speed could be even higher than 490 Mbps for all I know.

The iMac is now flying along and the LaCie is performing perfectly, although the internal fan is very noisy. I have positioned the drive as far away from the computer as the Thunderbolt cable will allow, but the fan noise is still intrusive. That said, it’s a small price to pay for the blistering improvement in performance.

Internal option

I have no doubt that installing a 256GB SSD into the iMac, in addition to the 1TB hard-disk, would be a cheaper option, even taking labour into account. Replacing the HDD with a 256GB SSD would be even cheaper because it doesn’t involve adding the necessary bracket to accommodate a second drive.

The LaCie, on the other hand, offers a hassle-free alternative, particularly since getting inside the iMac is not for the faint hearted.  It does have the advantage that you can keep the drive for alternative use after the iMac is sold.

Incidentally, if I you are in the market for a new iMac try to rustle up the extra cash for the SSD, either alone or in tandem with the mechanical HDD. You will not regret it. But, if you don’t order it you certainly will suffer regret.

This has been a hugely successful operation which has transformed my user experience on the iMac. Read speeds have rocketed by a factor of ten while write speeds have increased fivefold. This is a result by any standards.

Faster than the Air

What is even more surprising is the improvement over the MacBook Air’s 128GB SSD which was my previous benchmark for “fast”. The Lacie reads 3.5 times faster and writes over twice as fast. Bear in mind the Air is a late-2010 model and the current machines, with faster processors and newer SSDs, will probably equal or even surpass the performance of the LaCie.

Doing the deed

Setting up an external disk such as the LaCie as a main boot drive is very simple, expecially if you use a backup utility such as SuperDuper!

The first thing I did when I returned from the Apple Store with the new drive was to check out the storage on the iMac. I was plotting and planning while sitting on the westward-bound Underground, so I had a strategy already worked out.

It turned out I had used 250MB of the 1TB internal drive, so clearly that was not going to fit on the LaCie. I identified 85GB of media (mostly movies I had bought from the iTunes store) and I was able to move ths block to an old backup drive. In any case they can now be downloaded again from the store if needed.

Finally, I ended up with 165 GB which would fit on the LaCie. When I get a moment I can do more housekeeping and move less important stuff to an alternative location if necessary.


Having pruned the iMac’s internal drive to manageable proportions, I simply plugged in the LaCie to the second and last Thunderbolt port (the other is occupied by my Cinema Display) and fired up SuperDuper!.

SuperDuper! is perhaps the best backup utility for the Mac; at any rate it is the one I rely on. It costs $27.95 direct. In common with other similar cloning backup utilities it isn’t available from the App Store because it plumbs system depths that Apple doesn’t approve of. Everyone uses it, though, and there is no need to worry. An excellent alternative is Carbon Copy Cloner which is actually free (or, preferably, you should make a small donation to the developer).

Set up

I set the utility to copy the entire iMac drive to the LaCie and then to make the external drive bootable. As you can see from the screenshot, the SuperDuper! routine included repairing permissions on the iMac drive, erasing the LaCie and then copying the entire contents of the internal drive to the external SSD.

If you wish, you can leave bulky data on the internal drive, just as you would if, for instance, you had purchased a dual-disk iMac. However, if you want to see maximum benefit from the SSD you should at least have the applications folder on the faster drive. I chose to put everything there, largely because in my case it was feasible.

After the copy, SuperDuper! made the LaCie bootable and, finally, set it as the startup disk. The entire process took 87 minutes at an average (slow) 35 Mbps, obviously limited by the access speed on the mechanical hard disk in the iMac. This, I hope, is the last time I will see such a glacial pace.

After this process was complete I logged out of my user account before switching off the computer. If you do not do this, you will find yourself in the wrong user account, the one on the internal disk, after re-booting from the LaCie. This is potentially confusing and not immediately obvious.

Just log off, then switch off the computer. Reboot and the LaCie will take over. The internal 1TB disk will mount as a second disk. For the time being I have left all old the stuff on the iMac disk until I am absolutely sure there are no problems. Eventually, though, I will reformat this disk and reinstall OS X so it becomes an alternative boot disk. There will also be the best part of 1TB available for storage and management of larger media files and suchlike.

A word on FileVault and Time Machine

If you have been running FileVault encryption on the iMac, as I had been doing, you will find that it is not possible to convert the twin-disk LaCie to FileVault. I didn’t realise until I tried and got the error “Cannot convert an AppleRAID volume to core storage”. The situation with a single-volume SSD might be different, although I am not sufficiently clued up to know. It’s a pity, but it is not a deal breaker.

Time Machine will need some tweaking. I deleted the old Time Machine volume, set to back up from the internal 1TB disk and established new backup routine from the LaCie (which is now seen as the home volume) to the remote location (in my case a partition on my Drobo FS). I also excluded the internal 1TB disk from Time Machine backup since, for the moment, there is nothing there that I absolutely need. I can change this when I have sorted out what to keep on the internal disk.

Wrap up

If you are buying a new computer, an SSD drive is the most effective way of increasing performance. In the real world, in day-to-day activities, it makes more difference, subjectively of course, than the speed of the processor or the size of the RAM.

But if you already own a computer with a mechanical drive and a Thunderbolt port, an external SSD such as the LaCie is a sure-fire way to put new life into it. So far, I can thoroughly recommend it. I will report further if problems are encountered at any stage. 


  1. This is great ! I was looking to add one of these to my 27 inch thunderbolt display and move my iPhoto library to this. I have seen the specs but I love to hear real world examples

  2. Thanks for this, not many people have tried setting up an external thunderbolt SSD boot drive and I have been considering it . At the moment I have the Apple SSD option in my iMac but the disk space is getting smaller as more and more apps are added and a speed test shows this is not a very fast SSD (less than 200mbs read speed) – a newer SATA III should be much faster and 2 of them in the RAID O inside the Lacie should be even faster but I am still concerned about the Thunderbolt causing a ‘lag’ compared to an SSD disk on the internal bus – your review seems to suggest that there is no lag in use? I also have the Lacie Big3Disk Thunderbolt which uses 2 X 7200 drives and this is fast for data use, around 360mbps read time, I tried this as a boot drive but it was awful, OSX ran in slow motion and this made me thing that even if you have a fast 360mbps drive via the thunderbolt that it’s more than read/write speed, it’s also about access response times and I didn’t know if it was the disk access time or the thunderbolt cable that was causing it to run like slow motion. your blog suggests that the thunderbolt cable should work as fast as the internal bus – are you still using it as your boot drive and ignoring the read/write speed tests does it feel instant/snappy/fast in real world use? Many Thanks!

    • Hi Simon, I was using the LaCie as a both boot and data drive until a couple of weeks ago. I just sold the iMac so am down to one MacBook Air, so the LaCie is currently on a shelf. I had absolutely no problems with the set up and, as far as I could see, the performance in all respects was far better than the old internal HDD. In all I used it for about five months and it never missed a beat.

      My only reservation about the LaCie, apart from the expense (it is now cheaper than when I bought it) was a) the excessive noise and b) the fact that it comprises two linked 140GB drives. This means you cannot enable File Vault with the result that the drive is a potential security threat if it gets stolen or lost. There are other, better drives available. Somewhere I covered the possibility of using the Seagate GoFlex Thunderbolt adaptor with any 256GB or 512GB internal SSD. A friend borrowed my Seagate adaptor and got good results with an internal SSD.

      It’s a pity the drive is still not connected or I could have run tests. Since it doesn’t have File Vault the speed test software still works. I was getting in the order of 400 Mbps as I remember. I noticed absolutely no lag or problem.


  3. They now have a 1TB Raid SSD but it’s expensive at $1000 – I keep getting tempted by it 🙂 What you have said is very helpful because the last thing I would want to do is buy something like that and find that even though the sustained read/write speed is higher, there is any latency caused by the thunderbolt compared to the internal SSD. Thanks Mike!


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