I remember a while back people started talking about external video cards for laptops and such and now I rarely hear anything about them. So do they work or is it just unlikely that it could actually give a performance boost to computer games?
External video cards work well for text, basic graphics, etc. They are OK for largely static content. You could probably get away with web HD video (720p 12 frames/second).
However, they are not good for high resolution video, or gaming - the bandwidth on the USB port is not high enough even if you only have the video card connected to the USB host controller and nothing else.
So for business, programming, web surfing, email, etc applications they are great. Gaming, HD video, or other high performance visual use - no.
I fully expect, however, that with USB 3 we'll start to see performance video cards showing up for USB that can actually do real work. Still won't be able to fully compete with PCIx, but will be suitable for full HD, and most casual gaming (WoW, for instance, but fast twitch FPS gamers will notice the additional lag).
a promising announce regarding this technology was made by AMD in 2008
The technology is called XGP. The idea is to have an external box that you can connect to your laptop in order to boost its graphic performances when needed.
In my opinion the idea was great because you can use the box only when needed (at home/office) and save battery/energy in the other cases and maintain your mobility
Unfortunately there is only one product I know that implements this technology and it is the AMILO GraphicBooster equipped with a very nice ATI HD 3870
A good review for AMILO SA3650 + Graphic Booster can be found on Guru3d.
I hope we will have more solutions in the future.
Vidock 2 is probably the best solution on getting boosted graphics on a notebook atm (express card slot) but you also have to use a external monitor and performance is still lackluster.
more info here
I hope the tech gets somewhere... I would like to just have one laptop (the portable ones not desktop replacements) that can do it all and get rid of my gaming rig.
The problem is you never get enough bandwidth with an external video card. Normal videocards use PCI-X 16 interfaces, to talk with the memory controller of the mother board or the processor directly. PCI allows a bandwith of 32gbit/s, where USB 2.0 only does a lousy 480mbit/s. That's a factor 60 speed difference. So expect an external videocard to perform like a VPN client window. Good enough for some tool palettes, or watching a mailbox, but not much else.