USB Monitors? DisplayLink's Technology, Examined

Features
By Andrew Ku
published

Would you like to add another monitor, but find yourself out of display outputs? DisplayLink's technology employs the USB bus to extend your screen. The current implementation isn't perfect; we're more excited about the USB 3.0 hardware it has planned.

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.

Andrew Ku
24 Comments Comment from the forums
  • vdr369
    looking good, and pretty useful too, it is very useful for notebook users, does this product released in India.
    Reply
  • soccerdocks
    My notebook has 3 extra outputs. VGA, HDMI, and Display Port. That's plenty for me. I don't see too much of a use for this.
    Reply
  • nevertell
    When are we going to see DP connectors on most mainstream graphics cards and monitors ?
    Reply
  • SteelCity1981
    So when USB 3.0 ports goes to 100w this will eliminate the need for a display link i'd imagine.
    Reply
  • mister g
    nevertellWhen are we going to see DP connectors on most mainstream graphics cards and monitors ?When Nvidia does so on all their graphics cards, and when manufacterer's finally get the big idea and choose between paying for Displayport or to the DVI Consortium. IGPs also need to switchover or else it won't work.
    Reply
  • WyomingKnott
    soccerdocksMy notebook has 3 extra outputs. VGA, HDMI, and Display Port. That's plenty for me. I don't see too much of a use for this.For you, no. Other people might find it useful, though. Especially with ultra-portables or other compact devices that tend to have only USB and headphone ports.
    Reply
  • JohnnyLucky
    I didn't know modern laptops, notebooks, and ultra notebooks might not come with with connections for an external display. I would have thought a connection for an external display would have been standard. Way back in 1993 I purchased a Sony laptop that had an extra video connection. I used it to connect a 21 inch flat screen CRT monitor.
    Reply
  • jamie_1318
    I don't think I've ever seen a laptop without at least one external monitor plug. I don't see that being useful to me at least because I don't see needing three screens on a laptop in the immediate future. (I can already dual screen by using the Notebook's display).

    SteelCity1981So when USB 3.0 ports goes to 100w this will eliminate the need for a display link i'd imagine.
    laptops don't have 100w of power to output to a external GPU, they are probably not going to be on board with this technology. Besides which USB3 is nowhere near fast enough to feed data to a Graphics card in real time, without ever bothering to talk about latency or data-loss. It might be useful if they put very low end Graphics card and powered them off of the USB port, I don't see it becoming common enough to obsolete display port for some time.
    Reply
  • soccerdocks
    WyomingKnottFor you, no. Other people might find it useful, though. Especially with ultra-portables or other compact devices that tend to have only USB and headphone ports.My point wasn't that there was no use for this. Merely that there was a small market for this product.
    Reply
  • ram1009
    I find myself disagreeing with the whole premise of this topic. Why would anyone want to use a portable while there was a more powerful desktop nearby? It just doesn't compute. IMHO, portables are only to be used for those things you can't do on a desktop.
    Reply