Two forthcoming storage peripherals, the Promise Pegasus RAID and LaCie Little Big Disk, exemplify what Thunderbolt storage will look like. Each includes a RAID controller chip alongside the hard disk drives or SSDs inside the case. This is a stark contrast to today's storage devices, which use a peripheral connect like Fibre Channel, SAS, FireWire or iSCSI.
This makes them more like direct-attached storage (DAS) than the networked storage devices we rely on in enterprise data centers. They cannot be shared natively among multiple computers, and are therefore not suitable for clustering or enterprise applications. Instead, they will offer massive performance for creative professional workstations and similar I/O-hungry users.
The fact that a single cable can carry both storage and video data at once is attractive to this market. Photographers and videographers, for example, are prime buyers of Apple's 17-inch MacBook Pro laptop. These professionals love the idea of connecting just power and video to transform their laptops into workstations when they return to the studio. The performance of Intel's new Sandy Bridge Core i7 CPU seals the deal for them.
The two protocols used by Thunderbolt--PCI Express and DisplayPort--are both absolutely required, at least for now. Intel's Thunderbolt Controller requires a DisplayPort signal along with four PCI Express lanes to function, something most rack-mount computers just don't have. This means that add-on cards are unlikely, and an Intel spokesman confirms they are not forthcoming.
This is not to say that Thunderbolt will never come to the server space. An inexpensive interconnect with two 10G bps full-duplex channels is certainly an attractive alternative to 6G bps SAS. And moving the RAID controller to the expansion shelf would allow far greater performance in the scale-up storage market.
