Windows – 2560 x 1600 screen resolution not available when a second monitor is attached

nvidia-graphics-cardnvidia-quadroresolutionwindows 7

I am running Windows 7 (64-bit edition) and have a 30" Dell 3007WFP monitor which runs at a screen resolution of 2560 x 1600. This works perfectly until I try to connect a second monitor, and then the screen resolution on the main monitor immediately drops to 1280×800 and I can't change it back up to the correct resolution until I disconnect the second monitor.

The graphics card is a Nvidia Quadro FX 370. This has a dual link DVI connector (to which the 30" is connected) and a single link DVI connector.

The second monitor can run at 1920×1080 and is connected using a VGA to DVI connector.
Note, it does not seem to matter whether the second monitor is running at 1920×1080 or even at 800×600.

Windows reports 

Total Available Graphics Memory: 3839MB
Dedicated Video Memory:           256MB
System Video Memory:                0MB
Shared System Memory:            3583MB

Does anyone know if this a limitation with the video card, memory, drivers, connectors or something else?

If this is a limitation with the video card, can anyone recommend a PCI Express 16 card that would support at least this setup, but preferably support two 30" monitors both running 2560 x 1600. (I'm not into gaming etc, so it doesn't need to be very powerful)

Best Answer

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".

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