Hey guys, I'm looking at buying a few monitors and setting up an eyefinity display. I'm planning on purchasing an XFX Radeon HD 6990, which I belive comes with one mini display port to DVI (active), one minidisplay port to DVI (passive), and one mini display port to HDMI. I've never gone this deep into the field of graphics hardware, but have built a few PC's over the years. I'm really not sure of the difference between an active and a passive cable other than you (or at least I think) need an active cable for eyefinity. The 6990 has 1 DVI port and 4 Mini display ports on the back. So, I mostly just want to confirm that to set up an eyefinity with 3 monitors, I can use a DVI cable, the active mini display to DVI included with the card, and then something like It would also be nice if anyone could clear up for me the difference between an active and a passive cable.
Active displayport adapters actively use additional power to make sure the signal is converted properfly across the cable. Passive cables rely just on a passive signal translation. Eyefinity requires that the signals be actively converted for every monitor beyond the 2nd, hence why it comes with one active converter already.
I can't tell if the one you linked is passive or active, so just buy this instead:
Yup, for three way eyefinity you only need one active adapter. Basically an active adapter convinces a display port on the Radeon card that it is connected to a display port monitor and translates the signal to the appropriate device. Passive adapters are simply pass through devices and force the display port to act like an HDMI or DVI port. Passive adapters are kind of like how DVI to VGA adapters are used on video cards, where the card does all the work of treating the DVI port like a VGA port.
I don't remember why the active ports are needed for eyefinity, but that's just the way it is. I'm sure there is a good technical reason for it, but you probably need to go back to the 5800 series launch articles for a good lengthy explanation.
I didn't even realize that the first two monitors could also be using the displayports, and that within the first two monitors, if one's using a passive displayport adapter, that it didn't matter. Only the 3rd monitor and beyond needs to be an active displayport adapter.
Thanks so much guys! Just to make sure I understand correctly: Only one of the monitors needs to be connected via an active display port adapter. Since the card comes with an active and a passive DVI converter, and has one DVI port on the back, I can connect one monitor via DVI, another via passive display port to DVI adapter, and the last with the active display port adapter?