I have been trying to set up a 3 monitor array with my new system i have an amd 7870 where the IO on the back is two dvi's, Hdmi and a display port. And the monitors i have is an asus 24 inch monitors a dell like 24 inch and some other random hp monitor that i had lying around how i have them set up is both the dell and asus are on both dvis and then i have the other monitor on hdmi to dvi i also have display port to dvi adapter but still seems not to work. If anyone can help that would be great
It's likely that on your video card the HDMI uses the same output as one of the DVI connections, so you can't use both at once. You will likely have to use the Displayport connection along with each DVI connection to get things working.
As far as your DP adapter, does it work when it's the only monitor hooked up?