DisplayLink Tech Has Limitations; Future Is Bright
DisplayLink's USB 2.0-based products have a niche they're able to satisfy. Productivity-oriented workloads are easily handled by the company's hardware, making it easy to attach a monitor with USB, DVI, or VGA input. Its technology is not as suited to environments with lots of movement: movies, mostly, but games are a bad idea, too.
If you’re a home office user disinterested in heating up the room with multiple graphics cards, a couple of USB-to-VGA adapters give you a cheap way to go the multi-monitor route. And as an extra bonus, many USB-based monitors are driven by the bus, negating an additional power input.
While there doesn't seem to be a limit to the number of devices DisplayLink's technology supports, you can't go plug a monitor into each of your system's many USB ports, as both the CPU and USB bus would be easily overwhelmed. When the on-screen image changes quickly, video quality can suffer. The video above demonstrates how movement causes the text to tear. Instead, it's safer to consider a couple of screens a practical limit.
DisplayLink tells us it plans to leverage Intel’s Quick Sync technology to help accelerate the currently-taxing encode process. At that point (and assuming USB 3.0 connectivity as well), it'd be more feasible to expand out beyond one or two screens enabled by USB-to-VGA/DVI adapters without such a significant performance penalty. Our fingers are crossed that this will happen in the next few months. And by the time CES '12 rolls around we'll have hardware to test.