Thunderbolt devices are finally starting to trickle out into the market, albeit most of them so far have been storage devices and Western Digital's new My Book Thunderbolt Duo is no different in this regard. However, where WD has managed to excel compared to its competitors in terms of pricing.The My Book Thunderbolt Duo is available in either 4TB or 6TB, although currently only the 4TB model is available from WD's website. WD has gone for a more expensive setup with support for Thunderbolt in and out ports at the rear of the My Book Thunderbolt Duo which allows for daisy chaining of drives for improved performance. As with previous My Book products from WD, the My Book Thunderbolt Duo has user upgradeable drives.
WD doesn't provide any performance figures for the My Book Thunderbolt Duo on its website, but Engadget posted from figures showing off four daisy chained My Book Thunderbolt Duo drives with a read speed of 690MB/s and a write speed of 530MB/s. As such the write speed is slightly slower than what LaCie claims for its 2big with Thunderbolt interface which manages a write speed of 596MB/s when four drives are daisy chained, but the read performance is to WD's advantage as LaCie only manages 670MB/s.
Where the My Book Thunderbolt Duo really shines though is when it comes to the purchase price, as the 4TB is priced at US$599.99, $50 cheaper than LaCie's similar offering and the 6TB model comes in at US$699.99, a whole $100 cheaper than LaCie's equivalent. It's disappointing that neither company supplies a Thunderbolt cable with their device, but at US$49 a pop, we can sort of understand why.Source: Western Digital

Read more: WD finally launches My Book Thunderbolt Duo, is cheaper than competition by VR-Zone.com