The chassis of the 5big Thunderbolt looks familiar. That doesn't mean we don't like it, we're still big fans of the Neil Poulton design. The large, round blue eye in the front and the aluminium finish makes it a work of art almost. The rear is more functional, with five metal hard disk trays, two Thunderbolt connectors and the power connector.
The disks are locked, but can be unlocked quite easily with a coin or the included clip. Unlike the 5big NAS Pro, the Thunderbolt version only comes with disks. You can choose between five 2TB disks or five 4TB disks, so 10 or 20TB.
Since LaCie is owned by Seagate, it should be no surprise that in-house hard disks were used. The 20TB test model we received came with five Barracuda XTs (ST4000DX000), a disk that we haven't seen often as separate hard disk.
The LaCie 5big Thunderbolt is built around a number of ASMedia ASM106X controllers. It doesn't have a true RAID controller, however. To bundle disks you can use the Disk Utility in Mac OS, but by default, it comes in RAID-0. You can create configurations like putting a couple disks in mirror, putting a couple disks in RAID 0, or as separate volumes. RAID 5 is not possible. Windows is not (yet) officially supported, and we were unable to get the NAS to work in Microsoft's OS (ed: which is a real shame).
There is a big difference between the 5big Thunderbolt and the Promise Pegasus R4 and R6. These fit four or six disks, but have a true RAID controller as well. The absence of RAID-5 makes it so that you have to consider how you will use the LaCie 5big Thunderbolt. If you work with large video or photo files, it can be useful to have this much storage just a cable away. Or as an accessory for your Apple MacBook Air, Pro or Pro Retina. However, we would not recommend using the 5big Thunderbolt as back-up device if you leave all the disks in RAID-0. But if you put two disks in mirror with the other three in RAID-0, then you have an interesting configuration.
It's a bit of a shame that the 5big Thunderbolt comes full of hard disks. Using a couple of SSDs along with a couple of hard disks would be a useful setup. If you want to attempt that, you will need to use a bracket because the trays are designed for 3.5-inch disks only.
Thunderbolt is the relatively new connector that combines PCI-Express and DisplayPort. It lets you connect multiple peripheral devices to your computer and has extremely high transfer rates. The 5big Thunderbolt comes with two Thunderbolt connectors. You can use one for connecting the NAS to your computer or laptop, and the second one for adding other Thunderbolt devices or even a monitor. You can use pretty much any recent monitor since there are adapters available for Mini DisplayPort to HDMI, DVI or DisplayPort. That means you can also connect a monitor with single cable, and with a laptop you just need the Thunderbolt cable, the screen, and the power supply.
LaCie does include a Thunderbolt cable, which is a good tihng. Quite often you're forced to buy the expensive cable separately. Here you get a black, 50 cm Thunderbolt cable which is a bit short, so might want to buy the 2m cable from Apple anyway.
Installing the LaCie NAS device is simple. Mac OS X immediately recognizes the device, and you can use it right-away. A CD-ROM is also include with software and documentation. The software consists of a basic LaCie RAID monitor which you don't really need for using the NAS. Nevertheless, it's a bit odd that LaCie included the software on a disc instead of a USB stick, considering many Apple products don't have a DVD drive. The rest of this review you can read on Hardware.Info; Online retailer Jigsaw24 sells the LaCie 5big Thunderbolt for £1631 while the 10TB model costs £909.