Hi. I just installed Firepro W4100 with 4 monitors, Windows 8.1 64bit.
After a couple of minutes of me not touching the mouse or keyboard all the screens blank out. Touching the Esc key brings them all back ok until the next couple of minutes without me touching the keyboard or mouse.
Of course it seems like the PC power settings are set to two minutes but I have set them to 'Never' turn off the display.
Prior to installing the card I had 2 monitors using the built in video sockets without this issue.
Maybe there is a power management setting in the FirePro Control Centre I have not found!