Sonnet Announces Thunderbolt to ExpressCard/34 Adapterby Kristian Vättö on August 25, 2011 11:01 AM EST
Sonnet announced a Thunderbolt to ExpressCard/34 adapter today. The exact name of the product is the Echo ExpressCard/34 Thunderbolt Adapter and it is simply a box with an ExpressCard/34 slot and Thunderbolt output. It appears to be the first of its kind, although Sonnet has revealed a Thunderbolt to PCIe adapter previously. Sonnet is expecting late October availability. The adapter is compatible with any computer with Thunderbolt, which right now means any current generation Mac (excluding Mac Pro).
Sonnet claims speeds of up to 5Gb/s, which is on par with the ExpressCard 2.0 spec. However, since ExpressCard 2.0 is based on PCIe 2.x, there is 20% overhead due to 8b/10b encoding, so real world performance will be around 4Gb/s (500MB/s). For most users, this should be plenty - but for some power users, it might be a small shortage in case you have two USB 3.0 RAID 5 enclosures for instance. There appears to be only one Thunderbolt port too, hence this adapter does not support daisy-chaining (although it can be the last device of the chain).
While the bandwidth won't be an issue, the price might. This adapter will be priced at $150. You will also need a Thunderbolt cable which is $50, and an ExpressCard card. Sonnet offers a 2-port eSATA card for as low as $50, but it's limited to 125MB/s (most likely due to the SATA chipset). A USB 3.0 card goes for $70. That means the adapter, cable and card will set you back by at least $250. Obviously, there are non-Sonnet cards as well that may be cheaper but we are still looking at +$200. Due to the price, it can be hard to justify this adapter unless you really need the top-speed storage. Even then, it might be worth it to wait for some Thunderbolt enclosures (at least LaCie and OWC are working on them).
Thunderbolt isn't just about storage however. The interface carries PCIe so if you've got a non-storage ExpressCard/34 peripheral that needs a lot of bandwidth, the Sonnet solution may work for you.