Nvidia Quadro – Only Two Monitor Ports Detected on Quadro NVS 450

Your not missing anything at all. The Windows Experience score is quite strict in what it expects to calculate score. Unless you have some sort of indication of what the score is you would like to see, the actual score is fairly meaningless.

It is rare for me to see a graphics card give more then a 4.0 score in a notebook, unless your running an Alienware top of the range SLI.

IMHO The score is an indication but by no means a perfect indication of how well the card will perform. I have also seen a card's score drop between x86 and x64 installations. Unless your building this machine for high end gaming there should be no need to get the score higher, as it is more then sufficient to run day to day applications.

I have the ATI FirePro 2260, which has 256 MB of Video RAM. The specs state that it supports two displays connected via DisplayPort at 2560 x 1600 each. Unfortunately, I can't test as I don't own a high-res display like that. But don't rule out your graphics card simply because it has 256 MB of RAM.

The problem is more likely that the Dual-link DVI can drive 2560 x 1600 to a display, but the Single-link DVI can only drive 1920 x 1200. So I suspect (with nothing to back this up) that your card puts all its resources towards the dual-link connection when one monitor is plugged in. When you use the second connector also, the card's performance suffers significantly and it can't drive the higher resolution.

Tom's Hardware had an interesting blurb about this card:

The Quadro FX 370 is difficult to categorize. At $150 it is remarkably inexpensive for a professional board, but the performance is poor as you's [sic] likely expect. For simple computing tasks without great requirements it can be used, but you should consider whether you are saving money in the wrong area.

Looks like running two displays at decent resolutions is not considered a "simple computing task".