I have a workstation with a recent graphics adapter: Nvidia Gefore FX3700. As I want to use that adapter for long running CUDA programms, it might be very useful not to run also my desktop graphics on the same device. Unfortunately I cannot plug in further graphics boards into that machine. So I've searched and found that display link might be a solution: Not using the FX3700 for graphics but for CUDA and then using the DisplayLink for desktop. As I've read this I thought: "wait!, it would be awesome to just not plug a normal graphics board into the computer but a high performance CUDA device" which would have the enormous advantage of being portable.
But I guess this is not possible since I assume that no external interface has a memory bandwidth which capable of high performance computing (e.g. similar to PCIe), right?