gregck

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This is my current setup:

XFX 6870 with 3 displays connected.

1x sony 46'' hx850 (1080P) - connected via HDMI
1x LG 32'' TV (720P) conntected via HDMI to DVI adapter
1x Acer 23'' monitor (1080P) connected via dvi to mini displayport

I cannot get this to work properly, am i experiencing this problem because my LG TV is only 720p? i tried setting my sony tv and my acer monitor to 1368x720 (same as my LG) but it still doesn't display on all 3.

what am i missing?

could it be the wrong cable for the acer monitor? do i need some sort of weird active adapter to make it work? (when just using the acer monitor it works fine with that cable, though)

 
Hi

Here are the basic requirements:

Connecting multiple monitors for AMD Eyefinity technology couldn’t be simpler. There are four easy rules to remember:

1) The first two monitors can connect to the graphics card with any display output on your product: HDMI, VGA, DVI or DisplayPort.
2) The third (or greater) display must be connected to the graphics card via DisplayPort.
3) If your monitor does not have a DisplayPort connection, you will need an inexpensive active DisplayPort adapter for it. DVI to DP adapters can be had for less than $30 USD.2
4) Every family of GPUs supports a different maximum number of displays.

So you will need an active adapter if your Acer monitor doesn't have a display port.
 

gregck

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Hi, thanks for the answer, however i'm still unsure what to get exactly. My acer monitor is hooked up with a dvi (male) to displayport (male) cable. This is the cable going from my acer 23 to my 6870. http://www.amazon.com/gp/product/B003OBXHPC/ref=oh_details_o00_s00_i00

I assume what you are trying to say is that i will need an active display port adapter and NOT the cable i have.


Also, i am still curious if having (two) 1080p screens and (one) 720p screen. Will i need to change the resolution of my 1080p screens down to 720 in order for it to work?
 
DVI/HDMI have a limited amount of lanes to the GPU and DP/mDP does not. You usually can't run more than two displays with HDMI/DVI-D from a single GPU card, but DP has no such problem. DP uses different digital signaling, but HDMI/DVI-D have the same signaling and are really the same thing for their digital output, although with pins in a different arrangement, HDMI has audio, and DVI-D can have two links instead of one.
 

gregck

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@Blazorthon - thanks for the info. I knew a bit what you spoke about and it definitely helps, but i am still unclear about this. Will the above linked adapter work? and will i have to change the resolution of my 1080p screens if my 3rd screen is only capable of 720. Maybe i am misunderstanding you...?

thank you very much!
 


If the third screen is only 720p, then they would probably all need to run at 720p. I think that that adapter should work. Also, I'm pretty sure that 720p is 1280x720. I don't know for sure that your TV is 720p or 1366x720, but 1366x720 is not 720p, at least not the 720p that TVs refer to as HD.
 

gregck

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yes it's not 720p but it's also not 1080p. The stickied efinity thread says that all displays need to have the same resolution in order for efinity to work. Am i wrong to assume i'd have to lower the resolution of my (2) 1080p screens to 1360x768 in order for efinity to work?

thanks! you're so helpful blazorthon.