Graphics card only outputting to 2 monitors?

[Orange Furball]

I bought an AMD 7870 graphics card for my pc. The HIS 7870 GHz edition with 2gb of RAM to be exact. This care has one DVI port, one HDMI, and two mini display ports. I bought a mini display port (mDP) to DVI adapter and I have both an hdmi One and VGA coming in the mail tomorrow too. When I plug in a DVI cord, an HDMI cord, and the DVI to mDP adaptor, only two of the three monitors work.

Why does this happen? The box says it supports 6 displays, I'm using half that and it won't work. I could easily use 3 displays on my old GT 640.

Help!!!

 

[lunaoso]

Could it be the Mini Displayport adapter? Or do the HDMI/DVI monitors not work when the third monitor either?

 

[Orange Furball]

Could it be the Mini Displayport adapter? Or do the HDMI/DVI monitors not work when the third monitor either?

AMD Catalyst is only letting me use 2 monitors. It's not any of the ports as they all work. I could switch between the DVI , HDMI, and mDP adapter all I want, but I can still use a maximum of two screens only

 

[4JNA]

sounds like an adapter issue.

I’ve heard there are “active” and “passive” adapters. What’s the difference?
A passive adapter is the most basic type of adapter that can purchased. A passive DisplayPort adapter merely allows the GPU to communicate with a “language” that can be understood by the attached monitor, which has a differing connector.

As an example, using a passive adapter to connect a DVI monitor to a GPU’s DisplayPort connection will essentially cause that DisplayPort output to communicate with the “language” of DVI. As far as the GPU is concerned, it does not have a DisplayPort monitor connected, and therefore cannot leverage the benefits that DisplayPort enables (e.g. AMD Eyefinity technology).

In contrast, active adapters will actively translate the DVI signal coming from the monitor into a native DisplayPort signal for the GPU (and vice versa). A native DisplayPort signal is required for AMD Eyefinity because DisplayPort signals can be synchronized by the GPU to keep all of your monitors moving in concert.

This DisplayPort signal can also be synchronized with DVI and HDMI signals, but only two of these signals may be utilized on an AMD Radeon™ GPU. This is why AMD Eyefinity technology requires a native DisplayPort signal for the third (or higher) monitor.

you might have a go at the Eyefinity setup thingy to see if you can get a better solution using what you have/need to connect.

also looked up the User Guide at HIS. couple things to note;

Any number of Mini DisplayPort connections.
You can connect more than one display to a Mini DisplayPort connection using
a daisy chain configuration or a hub (multi-display support is made possible
through the DisplayPort v1.2 standard).
• Two connections between the dual-link DVI and HDMI connections.

might have a good look at 4.2.1 and 4.3 starting on page 12. if you have the connectors/adapters right, try following the sequence listed in 4.3 if you have not. i've had some that needed the monitor on first to 'see' them and then list them as an available output in config. best of luck.

 

[Orange Furball]

you might have a go at the Eyefinity setup thingy to see if you can get a better solution using what you have/need to connect.

also looked up the User Guide at HIS. couple things to note;



might have a good look at 4.2.1 and 4.3 starting on page 12. if you have the connectors/adapters right, try following the sequence listed in 4.3 if you have not. i've had some that needed the monitor on first to 'see' them and then list them as an available output in config. best of luck.

Oddly enough the VGA adapter I ordered appeared today, now I have three out of 4 monitors working and I'm just going to use the 4th as a secondary for my MacBook Air. Thanks for the help though I think you're right about the DP splitter adapter thing