DSLR Photography Forum

This external hard disk review from Engadget caught my eye, as it's one of the first (if not the first) external hard disk to use the new proprietary Thunderbolt interface on Macs that were launched recently. The Thunderbolt interface supports (theoretical) speeds of up to 10Gbps, compared to USB 3 which only manages 5Gbps and e-SATA which goes up to 3.2 Gbps.

http://www.engadget.com/2011/11/08/lacie...sd-review/

To take advantage of the bandwidth, the Little Big Disk Thunderbolt SSD uses 2 x 120 GB solid state drives in a raid 0 configuration (data striped across both so you get both drives pumping data through). In their tests, they got close to read speeds of 480 MB/sec and write speeds of 254 MB/sec. Note, those figures are in Bytes, whereas the throughput speeds are in bits, so if you convert (x8), they turn out to be roughly 3.8 Gbps reads and 2 Gbps writes, which is still short of the theoretical maximum, but still extremely impressive.

Of course, when you come down to price, it starts to get a bit crazy at $900. Also, 240GB isn't very much data at all, but I'm sure they will be able to squeeze in larger SSDs if your wallet is big enough.

The Thunderbolt technology is appealing and my iMac *could* make use of it, but 120GB is too small to be of any real use to me. I'm dealing in TB of disk requirements these days...

I'm not sure what LaCie was thinking including this in the "Little/Big" family, but this drive is clearly aimed at people who need a very fast scratch disk, such as for video editing. For that, this would be awesome.

Not that I need or want one, but still, it's nice to know that such a thing exists.

matthew Wrote:this drive is clearly aimed at people who need a very fast scratch disk, such as for video editing.

Yes - it would be wonderful for that, and the size of the drives would be sufficient. But its pointless having scratch disks in a RAID configuration, isn't it?

..or am I missing something?

In this one particular configuration of RAID, it makes sense. Using the "striped" RAID 0 writes part of the data to each disk, so there's no redundancy, but it doubles the systems' potential read/write speed and both drives create the available capacity. That this one a 240GB drive, which would be plenty for a scratch disk.

(Actually, raid 0 is the opposite of redundancy, since if either of the two drives fails, all of the data is gone. But shipping the drives in this configuration means that the marketable capacity is double that of a redundant RAID 1, so a HDD box that contains two 500GB drives will be sold as a 1TB unit, which is a size that people might accidentally try to use for long-term storage. I do know someone who recently lost a lot of data when a drive sold this way crashed.)

You're absolutely correct with the RAID 0 config - it doubles the chance of failure, which is scary. However, if you implement a good backup strategy, you should be adequately protected.

The suggestion of use as a scratch disk makes sense as well - in which case you wouldn't care for the contents if it failed.