I have been running my 3XS system for a good few weeks without problems on 3D work. I specified the new Nvidia Quadro 4000 card.
I have added a second DELL 2209wa monitor for a dual monitor system.
One monitor is attached to the Quadros DVI port to the priniciple DELL 2209WA DVI port the new one is attached via the Nvidia Displayport to DVI adapter then tyo the 2209WA's DVI port.
The second monitor work fine for 30 minutes and then went into powersave mode.
To try and resolve the issue I have:
Swopped over the monitors, they both work on the Quadros DVI port.
Reinstalling the Quadro drivers, installing the new Quadro drivers.
All to no avail.
On reading post on the internet it seems the next port of call is the Nvidia adapter that came with the card as there are reports of these failing.
I have posted a support query.
This card is professional product and at £900 plus. It should be capable of running dual monitors for professional work.