Thunderbolt is the absolute fastest consumer interface available for users who want high-speed external storage. We proved this in our Pegasus R6 review where we sustained transfer rates of 1GB/s (8Gbps) from an array of five SF-2281 SSDs. There are just two problems with Thunderbolt today: 1) It's practically only available on Macs, and 2) the Promise Pegasus is extremely expensive.

In its cheapest configuration, the 4TB Pegasus R4 with four 1TB 3.5" HDDs will set you back a cool grand. Want the 6-bay version? That'll be $1500. And the top of the line 12TB model is priced at $2000. Less than $500 of that $2K bill is the retail cost of the hard drives, the rest is all chassis, controller hardware and of course manufacturer profit. As great as the Pegasus is for professionals who need the storage and performance, it's priced too high for most consumers who also want fast external storage.

LaCie hopes to offer an alternative for those who want more affordable Thunderbolt storage. Note that I said more affordable, and not just affordable.

Last month LaCie released its Little Big Disk, a two bay (2.5"), all metal Thunderbolt enclosure. Like Promise, the Little Big Disk is available only with drives pre-installed. Sadly our hopes of meeting a BYOD Thunderbolt enclosure remain unfulfilled. LaCie's pricepoints are a bit more attractive than Promise's, although you are getting a far lower performance solution in return:

Thunderbolt Storage Lineup
  # of Bays Drive Configuration Default Capacity Price
LaCie Little Big Disk 1TB 2 2 x 500GB sw RAID-0 1TB $399
LaCie Little Big Disk 2TB 2 2 x 1TB sw RAID-0 2TB $499
Promise Pegasus R4 4TB 4 4 x 1TB RAID-5 2.7TB $999
Promise Pegasus R4 8TB 4 4 x 2TB RAID-5 5.7TB $1499
Promise Pegasus R6 6TB 6 6 x 1TB RAID-5 4.7TB $1499
Promise Pegasus R6 12TB 6 6 x 2TB RAID-5 9.7TB $1999

The drives are available on Apple's online store as well as Apple's retail locations. The 240GB SSD model is still several weeks away from availability, so what we're looking at today is the 2TB HDD solution. I only had a limited time with the Little Big Disk and wasn't allowed to take it apart, so forgive me in advance for the brevity of this review (although I did try to hit pretty much all of the highlights of the device).

The Chassis

LaCie Little Big Disk Dimensions
  D W H Weight
LaCie Little Big Disk (2TB) 140 mm 40 mm 85 mm 650 g
Promise Pegasus R6 (12TB) 242.9 mm 188.9 mm 254 mm 9.25 kg

As its name implies, the Little Big Disk is pretty small. The blue orb at the front functions as a power/activity LED as well as an on/off button. The design is beautiful and the construction very solid. LaCie likes to think the Little Big Disk is small enough to be portable, but its weight may discourage you from taking it wherever you go. Even if you don't travel with it, the Little Big Disk's size makes it a considerate resident on a desk.

There's not much assembly required, the unit is ready to go as is. If you want a bit more stability however, LaCie supplies a small stand in the box that slides onto the bottom of the unit to prevent it from toppling over. The Little Big Disk does not come with a Thunderbolt cable, so be sure to tack on another $50 to your budget. Power is supplied via an external AC adapter that ships with swappable plugs for use in the US, UK, Australia and the EU.

Inside the chassis are two 2.5" SATA hard drives connected to a basic, non-RAID SATA controller. The SATA interface is then routed over PCIe to an Intel Thunderbolt controller and finally sent out via a Thunderbolt cable to your Mac. LaCie was pretty strict on not having us take apart its review sample so the best I have are the shots of the internals we saw surface a while ago. A closer look seems to indicate a Marvell SATA controller (not a surprise) but it's impossible to tell whether or not it's a 6Gbps solution.

Given the absence of a RAID controller, LaCie relies on OS X's software RAID. By default a single Little Big Disk is configured as a two drive RAID-0 array. For the 2TB model that means you've got 2 x 1TB drives inside, and for the 1TB model that's 2 x 500GB drives.

My LBD sample had two Samsung HN-M101MBB 1TB drives inside. These are 5400 RPM 3Gbps SATA drives with an 8MB buffer, 5W max power draw and 2.2W typical. Interestingly enough, the first user who posted pics of a dissected LBD found a pair of 7200RPM Hitachi 7K750 (500GB) drives in his. I don't have enough of a sample set to know whether or not all 1TB models use 7200RPM drives and all 2TB models use 5400RPM drives, but it looks like you can expect to see some variance between models.


With only a pair of 5400RPM 2.5" hard drives, the Little Big Disk isn't going to break any performance records. In fact, had LaCie outfitted the chassis with a single SSD we would've seen higher performance than the two-HDD setup it comes with from the factory. That being said, if you're a Thunderbolt Mac owner, the LBD is the second fastest external solution you can buy today (without resorting to an ExpressCard to eSATA bridge or something similar):

LaCie Little Big Disk Performance
  Sequential Read Sequential Write 4KB Random Read (QD16) 4KB Random Write (QD16)
LaCie Little Big Disk 2TB (RAID-0) 207.0 MB/s 205.0 MB/s 1.22 MB/s 0.56 MB/s
Promise Pegasus R6 12TB (RAID-5) 673.7 MB/s 683.9 MB/s 1.24 MB/s 0.98 MB/s

Sequential performance is obviously the LBD's strength, at over 200MB/s in both of our Iometer tests. This is the sort of performance you'd see moving large files (e.g. videos) to/from the device. We are completely limited by drive performance here, Thunderbolt is capable of at least 8Gbps as we've seen from our tests and the Little Big Disk is only pushing 1.66Gbps. Random performance is of course what you get from mechanical storage. An internal SSD will do better for your OS and apps, but for use as backup or media storage (photos, videos, archives, etc...) you'll see performance closer to 200MB/s.

Thunderbolt Display Compatibility

One of the first things I tested was to see if the audio corruption issue I experienced with the Pegasus and Apple's Thunderbolt Display was present on the Little Big Disk. To recap, if you were playing music on the TB Display (via its internal speakers or USB audio connected directly to the monitor) while writing tons of data to the Pegasus you'd eventually get audio corruption. I tried the same test with a Mac connected via Thunderbolt in place of the Pegasus and didn't see an issue. I repeated the test with LaCie's Little Big Disk in place of the Pegasus and once more, didn't see an issue. The only time I got audio corruption was when I plugged in the LBD while the Thunderbolt Display was already playing music. Resetting the audio codec at that point fixed everything and I didn't see the problem resurface. As I alluded to in our Thunderbolt Display review, Promise developed and released the Pegasus before the TB Display was available. LaCie had the luxury of continuing testing and validation after the TB Display was launched, which likely gave it a bit of a leg up in this department.

Interestingly enough, I couldn't get the LaCie LBD to daisy chain with my Pegasus, although I'm not sure which device was at fault there. If I connected the Little Big Disk after the Pegasus, the LaCie drive wouldn't work. If I connected the LBD before the Pegasus, the Promise array wouldn't work. The Little Big Disk did work properly connected directly to my MacBook Pro and Thunderbolt Display. Update: Moving the Thunderbolt Display to the end of my Thunderbolt chain (rather than the middle) fixed this issue. After I did that, both the LBD and Pegasus appeared. I was then able to move the Thunderbolt Display back to its original position in the chain and both drives continued to work as expected.

Power Consumption

Thunderbolt is capable of delivering 10W to a connected device, however the drives alone in the Little Big Disk can consume as much as 10W (2 x 5W) during startup. Add in the SATA and Thunderbolt controllers and you can quickly understand why the Little Big Disk needs an external power supply.

Power Consumption Comparison
  Idle Load (Sequential Write)
LaCie Little Big Disk 2TB (RAID-0) 7.8W 12.1W
Promise Pegasus R6 12TB (RAID-5) 64.3W 69.1W

Power consumption isn't in-line with expectations. At idle the Little Big Disk pulls just under 8W, while under load (sequential writes) it's a hair over 12W.

Noise & Thermals

The Little Big Disk is cooled via a single internal fan. The size of the chassis limits the fan size, which puts LaCie in an interesting predicament. LaCie could either allow internal temperatures to get uncomfortable warm and keep the chassis quiet, or keep temperatures in check and sacrifice noise. It picked the latter.

Under normal operation the 5400RPM drives in my LBD sample remained at around 44C. The highest I ever saw the drives hit was in the low 50s. Internal drive temperature doesn't seem to be a problem with the Little Big Disk, which is good news.

Unfortunately the chassis is loud as a result. It's louder than both the Promise Pegasus and a 15-inch MacBook Pro (at normal temperatures, under load with fans at full speed the MBP is louder). Thankfully there's no whine, it's just the sound of a lot of air being moved via a relatively small fan. It almost sounds like you've turned on a small desktop somewhere in the room. The noise is my biggest complaint about the Little Big Disk. My only hope is the SSD configuration will be able to back off on the cooling requirements and deliver a quieter solution.

Final Words

Thunderbolt products are finally starting to roll out. The Pegasus was a good start, and the Little Big Disk gives customers a more palatable price point. To hit the lower price LaCie does sacrifice a bit on capacity and performance. The move to 2.5" hard drives and only being able to accommodate two of them in its small chassis limits peak performance to around 200MB/s. Compared to USB 2.0 and FireWire 800 options however, that's not bad at all. Even compared to GigE, you're still looking at a significant performance improvement. If you do a lot of large file transfers onto your external storage, the Little Big Disk will likely be a huge step up from your current solution.

My biggest complaint about the Little Big Disk is its noise. While I'd rather accept a louder solution than one that kept drive temperatures uncomfortably high, I'd much rather not have to choose between either. LaCie may have painted itself into a corner here by aiming for such a small device size. If you're a stickler for quiet computing the LBD may bother you. If you're fine with some extra fan noise then you'll be just fine.

I do like the Little Big Disk chassis a lot, I only wish LaCie would offer it sans-drives to hit an even more affordable price point. The empty chassis game is a race to the bottom however and I don't see LaCie wanting to play in that space. We'll have to wait for other manufacturers to jump on the Thunderbolt bandwagon before we see a BYOD solution.

If I can't have an empty chassis, here's hoping that LaCie's forthcoming SSD version will be everything I hope for in an external Thunderbolt solution. With lower cooling requirements it could address the noise issues and performance should obviously go up. The only question is, will LaCie be able to deliver a solid-state Little Big Disk at a reasonable price? We'll find out soon enough...

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  • repoman27 - Tuesday, November 1, 2011 - link

    Why not just buy one of the LaCie solutions that is available?

    Although the whole point of USB 3.0 is that it's designed to be fast AND cheap. In order to take full advantage of both facets on a Mac, it makes more sense to wait 5 months, at which point it will be shipping already baked into Intel chipsets along with native Mac OS X driver support.

    With a single 2 disk RAID-0 HDD array as the only device connected to the controller, there shouldn't be much performance difference between Thunderbolt and USB 3.0—the disks are the limiting factor. With SSD's, USB 3.0 tops out around 370 MB/s but is usually limited to less than that by the performance of currently available silicon and drivers. Thunderbolt can provide more throughput than a single SATA 6 Gbit/s controller, but in the case of the LaCie TB LBD, the current lack of native Mac OS X driver for the Marvell 88SE9182 limits performance to around 300 MB/s give or take.

    This makes Thunderbolt, as it stands, a considerably more expensive option than USB 3.0 for a single device with similar performance. However, once you hang more than one device off of a single controller, I'm pretty sure Thunderbolt would dominate in a big way.
  • FelixO - Tuesday, November 1, 2011 - link

    Thanks, that's useful.
    I don't have a Mac, but was wondering whether to buy a USB 3.0 drive now or wait for Thunderbird on PC.

    I think I'll go for USB 3.0.
  • joex444 - Tuesday, November 1, 2011 - link

    Fool of you! No way is Thunderbolt the fastest external connection. All your Pegasus R6 benchmark did was show Thunderbolt is fast. I did not see any comparison to an external SAS array, for example, driven by a hardware controller on PCIe x8. Fast, sure. Fastest? Go f* yourself.
  • Penti - Tuesday, November 1, 2011 - link

    Thunderbolt is PCI-e 2.0 x4 of course it will be slower then an internal PCI-express x8 hardware RAID expansion card. If you like to use an internal card with the x4 limitation you can get a Thunderbolt PCI-e cabinet though. Should be able to get you beyond the pegasus in performance. But external SAS-connectors on an Internal PCI-e card isn't the fastest you can go externally either you can have external PCI-e x16 or Infiniband at dual 40Gigabit through a PCI-e 2.0 x8 slot that would have the same (bus) hardware limit as your raid-card. Don't see how all that is relevant though.
  • MGSsancho - Wednesday, November 2, 2011 - link

    If you really wanted to you could compare tunderbolt to various devices in the Direct Attached Storage market but you have to compare products in similar price ranges. I think you are spot on Penti, all of that is irrelevant just as comparing a few thousand dollar Pegasus array to a $70k flash array with 60 Intel ssds

    Last I checked, thunderbolt was not exclusively an interface for storage alone.
  • Penti - Saturday, November 5, 2011 - link

    Well there are Fibre Channel Thunderbolt adapters for storage devices are there for USB 3.0? No. It obviously has it's point and different strengths. Obviously you can't really do anything comparable with any other bus-interface if it's fastest or not is not the point. It's faster then ExpressCard and has found a great space in the professional business area. Connecting professional hardware to a laptop is what they achieve even if this (Lacie) solution would probably work better on USB3.0. Which they will get officially with Ivy Bridge any way. You have to remember that it's an interface for laptops, ultraportables and SFF PC's. Not about the fastest external interface possible. Obviously if that was the goal then laptops would be severely limited by it's internal capacity. While workstations could do like external PCI-e x32. 2x40Gigabit network is possible in servers but count it out in laptops.
  • connor4312 - Tuesday, November 1, 2011 - link

    The image of the hard drive in the hand; Photoshop much? Anyway, ducking out $400 plus $50 for a cable I'll loose within a week, no thanks.
  • Juddog - Tuesday, November 1, 2011 - link

    It's too bad LaCie's support is so shoddy; their products are decent but when it comes to replacing a failed drive it turns into a nightmare. For one thing they won't let you open the case without voiding the warranty (in order to wipe the drive contents, for example). Second failure for their support is that it's terribly slow. I spent literally 28 days arguing back and forth with them and finally they opened up the option to let me send in the drive for replacement. Personally I will never buy another LaCie product again, not because of the performance or form factor (they are very nice looking), but simply because their support is utter garbage.
  • chrisHartwig - Friday, November 4, 2011 - link

    I've own a 2To Little Big Disk and I'm very disapointed... Actually, I'm in touch with LaCie's support, searching for a solution to extreme slow downs. Using Black Magic Design's Speed Test or xBench, I can't get consistent results as they vary from 150MB/s to 10MB/s.

    Seems like it's related to heat, as I've already observed sharp fall of performance at the exact time the fan was blowing faster...

    Powering down the disk solves the problem, but it slows down again in a few minutes.

    It sometimes slows to a crawl, like 10MB/s, rendering it unusable for my usage (pro photography).

    Is someone else experiencing similar problems ? LaCie suggest I should try swapping computer-Power supply-Thunderbolt cable, but I just can't... If others have similar problems, then it's purely a design flaw. If I'm the only one, something is defective...
  • BastaLaCie - Monday, December 19, 2011 - link

    I am also professional photographer, living in Italy with Studio in Nice France.
    I am done with La Cie,
    I bought a 1TB Thunderbolt hardrive at the Brescia (Italy) Aple Store, yesterday sunday (Christmas shopping so it was open) afternoon, 420 euro (including Vat) = 545 US$, and the store did not even know that the cable was not included... I went back today and bought the Aple TB cable for 50+US$, I did try the hard drive: slower than a Fire-wire 800 on a 6TB... La Cie!....
    Out of the fact that having to buy the cable is obscene, I was not impressed at all, and I have a bunch of screen shots to document what I write, do not hesitate to contact me by e-mail to receive copy of these sceen shots. Forget about 10GB/sec!!!!....
    So I went back a third time to the Aple Store, and gave them back the hard-drive and get my money back. End of the story...
    I am done with la Cie... especially with their Rugged 1TB (I had 2 --TWO-- failing), other photographers in Cannes, France, had the same problems with the same 1TB Rugged (Jerome Kelagopian, Franck Spire, Pascal Pronier, I can give their e-mails if needed), La Cie PERFECTLY know that they had problems with their 1 TB Rugged Fire Wire 800 + 400, I have very long communications with their "Support" team in Milan to prove what I write, but they NEVER recall these Hard Drives, as any SERIOUS, HONEST and RESPONSIBLE company would have done.
    Magazines or web pages promoting these hard drives (Rugged 1 TB Fire wire 800+400) should be ashamed... I lost a LOT of pictures by doing the back up of my pictures on these hard drives.... and when I contacted the "Support" through the web, they basically answered that I should NOT have used them for back up!.... That it is clearly written in their warranty that they are not responsible of any failure... etc.. etc...
    What REALLY disappointed me with La Cie is that they are PERFECTLY aware of the problems MANY people had with their Hard Drives, they know that they probably had a good number of bad hard drives mounted in their Rugged, but they did NOTHING to recall them (which would have been easy by checking the serial numbers)...
    And even if I use their 6TB, 3TB, 2TB, which so far did not gave me problems, doing an immediate DOUBLE back up on Western Digital hard drives, I am done with La Cie lack of responsibility, bad support, and lack of seriousness.
    That is why my nickname here is Basta La Cie = Enough with La Cie and I can sign with my real name:
    Marc Paris

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