I know this can be done as I have done it in the past with this card and my computer at home is currently registering a 3rd monitor but wont let me activate it as a usable monitor. it is in "passive" mode for lack of a better term.
I have a Dell precision t3500 tower with an amd firepro V4900 graphic card. Card has (1) DVI and (2) DP.
I just ordered a DP to DVI (apparently passive) for my third monitor thus leaving me with the current set up:
(1) monitor running DVI to VGA from DVI output,
(1) monitor DP to DVI female with DVI male to male cable
(1) monitor with new DP to DVI Male (passive)
my question is, since the V4900 card only allows a max of 2 DVI signals then others are required to use a 3rd monitor (like VGA or DP to DP), and I am technically using 2, could I order a DP to VGA adapter for the third monitor or would ordering a new DP to DVI active cable be a better option? my third monitor is only capable of supporting DVI and VGA. no other signals. I suppose I could order a DP to VGA as well but I would assume that would need to be active too.
My last option is to use a USB to either DVI or VGA display if all else fails.