How good are USB video cards?

How good are USB video cards?

Summary: Are cheap external USB video cards good enough to power an extra monitor or five, and what are their pitfalls? Won't handle 3D acceleration? Take up valuable CPU cycles? Leave dirty dishes around your desk and have a bad odour?

TOPICS: Dell, Hardware, Intel, PCs

After I published my pseudo-scientific investigation several weeks ago into the widespread problem of phantom monitor pain, quite a few readers wrote in with one simple question. "Renai," they earnestly asked me, "why don't you simply get yourself a second monitor at work?"

The answer, it turns out, is not as simple as that. But then, it never is for people like me who tinker with their hardware too much.

My workstation is a Dell Optiplex 755, which in general terms I'm happy with, as it has a nippy Core 2 Duo CPU and 2GB of RAM. Those of you who have worked in publishing houses will know this is a bounty of processing power not normally found on journalists' desks.

However, the one problem with my slimline Dell is that its graphics card doesn't come with two monitor outputs ... in fact it doesn't even come with a DVI output. Instead, it has but a solitary VGA plug to make do with.

Consequently, the only ways I can get a second monitor working is to buy a half-height video card and do some delicate surgery on my Optiplex, or to simply buy one of these new-fangled external USB video cards people have told me about.

An external USB video card (Credit: Winstar)

You can pick one up from Aus PC-Market for slightly over $110, or more if you want a really fancy one. A cursory look at the specifications shows that most of the units can provide resolutions of up to 1600x1200 or even more, and work on a variety of operating systems.

I'm still slightly suspicious of such a solution though, as I'm not sure of the extent to which the USB 2.0 specification is geared to support extra displays (especially when it comes to 3D acceleration), and whether there would be an impact on my CPU from the extra gear.

What has your experience been with external USB cards? Good, bad or ugly?

Topics: Dell, Hardware, Intel, PCs

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.


Log in or register to join the discussion
  • They're a fair compromise

    The external display adapters work by sending a compressed copy of the video frames over USB, so frame rates will not be high enough for 3D (gaming?) where most if not all of the screen is changing. Better to keep graphics like that on your main monitor and use a USB monitor for writing/web browser windows.

    The USB solution will take some of your CPU power as it compresses the video and sends it over USB.
  • Multiple monitor madness

    There are good and bad ones. I managed to find a targus USB laptop dock at work. It has several USB ports, serial, audio, network and VGA. I have disabled all bar the VGA and serial. It is painfully slow though so it runs the screen that has my email in it. It also has issues occasionally where you plug something in and it crashes and you have to disable the screen in windows and leave the power to the dock unplugged.
    Not ideal, but free was the right price. I have heard of Nvidia doing graphics cards on USB but I have no idea how they can be quick enough to game on with just a single usb's bandwidth.
    You can get splitters on DVI and a while ago there was a hp that supported it on VGA, so maybe your card supports it?
    You could always put a second graphics card in the pc too, a pci one is pretty cheap and will be faster. Or you could use synergy and a second computer to drive the second screen:
    I used to do this at work and the second screen just ran email and documents for refference, the other screen was my laptop. I also at one stage had 4 screens going at home three laptops and a desktop, much fun.
  • ok

    no good for any video work as the memory buffers are usually 8MB, and with a top speed of 400Mbits/sec of usb that is about all it will handle anyway. but for outlook and word they work well.
  • As expected

    That's pretty much what I expected.
  • A lot of options!

    A lot of options there ... I don't want to get too complicated though ... it's my work PC and already has a stack of stuff hanging off it ;)

    I want to add a scanner at some point, gotta get around to that as well.
  • Aero support

    Do they have the balls to support Aero?
  • Aero

    hey Mel,

    they surely do, I am running Aero on Win7 on my second desktop through USB video card right now.
  • Nice!

    I might have to try one then. My HP desktop is a few years old now but still a great machine in as-new condition. Sadly, it only has one expansion slot and that is taken up with the wireless card, preventing the addition of a decent video card.
  • SWAP EM' !!

    Hey Mel :)

    Get a Wireless USB,(they work well for most people) and then you'll have a free expansion slot for a decent graphics card.

    Hope this Helps ;)

    Later, RIPP.
  • ur wireless card would be in a pci slot u should have a spare agp or pci express slot
  • I'm interested in finding out if the external video card is......

    I'm interested in finding out if the external video card would be a possible solution(temporary) for my situation.

    I have an Alienware Area-51 M5500i-R3 Laptop that I'm not able to get better than 640x480 with 4...yes 4 bit resolution.

    Would this or any external video card act as a replacement video card in my circumstances until I can find a MXM card to replace my old card(geforce 7600 Go)?