The results achieved might look fairly slow compared to the 3Gbps (375MBps) theoretical limit of SATA II, but there are some restrictions on the interface of the Two Big. LaCie quotes a maximum transfer rate of 115MBps which is closer to the older SATA standard. However, if you compare this to the fastest external interface with is FireWire 800 which offers a maximum transfer speed of 100MBps it's still quite fast.
The first two tests consist of files copied from a 7,200rpm SATA drive to the Two Big and the time it took to copy these files across. The 12GB test comprised three 4GB files, and the 15.2GB test consisted of a large amount of mixed-size files. The theoretical tests came fairly closed to the stated transfer rate limit and shows that this is a very fast setup.
There's really only one downside to the Two Big and that's the price. At £689 inc. VAT or $949 in the US, it's quite a lot of money to fork out for 1TB of external storage. Nonetheless, I'm thoroughly impressed by the Two Big. It's an excellent product and, to my knowledge, there's nothing else like it on the market.
LaCie has come up with a truly unique product with the Two Big, although I have no doubt other manufacturers will follow its lead. The Two Big isn't cheap, but isn't over-priced by any means. It offers excellent performance and the advantage of user-swappable drives once larger capacity units are available. Overall, the Two Big is a great solution for anyone looking for a huge, fast external storage rig.