GPU Performance vs. Dual Monitors

[burgerbyte]

I want to build a new scientific computing PC with GPU dedicated to basic matrix algebra routines (large matrix - vector multiplications and additions etc of double numbers).

For basic development purposes, I want a dual monitor system, which brings up a couple of basic questions that I cant find answers to:

1) does using the monitor output of a GPU card, while simultaneously computing, effect the overall performance spec of the GPU?

2) if the CPU has built in graphics - can one monitor be plugged in to motherboard, or do I need a GPU card with dual monitor outputs?

3) Will I see much difference between a 2GB vs 4GB card? How do I know how much memory will be optimal?

I'm considering a gtx 680 based card... any recommendations? How do different flavors/vendors of this chipset compare?

Thanks...

[David (PassMark)]

1) No. It shouldn't to any measurable degree.


2) Many integrated video cards now support dual monitors. So you could run all your monitors off the motherboard, then get something serious like a nVidia TESLA card, or the Intel Phi card, that doesn't even have a video output.

3) Optimal memory depends on the scientific calculations you are doing. (you don't need 2GB for a dual monitor desktop).