Elsa of Japan, a leading supplier of various professional solutions, has quietly added an expansion box for PCI Express add-in cards with Thunderbolt interconnection. The device is designed for special-purpose cards, but it can potentially be used to connect graphics cards to PCs using Thunderbolt interface.
Elsa Magma ExpressBox 3T has three slots - two PCI Express 2.0 x8 and one PCI Express 2.0 x4 - and 220W internal power supply unit. The expansion box is primarily designed for video-capture, media transcoding/encoding, audio processing add-in cards or high-end solid-state drives with PCI Express interface. The expansion box fully supports daisy-chaining and other advanced functionality that Thunderbolt has to offer. The box is compatible with Microsoft Windows and Apple Mac OS X.
The main aim of the Magma ExpressBox 3T is to add functionality (e.g., professional audio card or video-capture capability) to notebooks and all-in-one desktops with Thunderbolt interface, such as Apple MacBook Pro and iMac, which are used for professional purposes. Nonetheless, in some cases it may be possible to install a graphics card into the expansion box - provided that internal power supply can handle significant load and there is a driver available - in order to boost graphics processing performance.
While it is clear that external graphics cards have a lot of potential as a lot of people want to play modern video games or use professional applications on their portable PCs on external displays that support high-resolutions, Thunderbolt as it is now may not be the most efficient technology to connect graphics cards to notebooks. Current version of Thunderbolt only supports 10Gb/s (1.25GB/s) bidirectional bandwidth, whereas modern high-end graphics cards require much higher transfer speeds provided by PCI Express 2.0 x16 (8GB/s) or even PCI Express 3.0 x16 (12.8GB/s) slots.