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Ive just bought the top end ATI Radeon card with 2 normal monitor ports and a HDMI.

The idea was to continue using my dual screen setup as always and to use the last plug, the HDMI on my TV. I got a new 52 inch HD TV with all the necessary bits. This should work fine.

But.. in Display Properties I still get only my 2 monitors up as options. Not the Digital TV.

When I unplug 1 monitor and restart the computer, I get the TV and the other monitor. But never all 3 at the same time. Why is this ? Where can I go to tell it that I need all 3 screens at the same time.

Also I get a message saying my gfx card also gives sound through the HDMI cable.. But the TV tells me its recieving a sound format that it does not understand. Any ideas on that too while were at it ?

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My understanding is that in order to have more than 2 displays, you need to have DisplayPorts. I'm not sure exactly why this is, but it has to do with a hardware limitation of how DVI (and thus HDMI) work. You can use only 2 of the DVI controllers at once; that can be either 2xDVI connectors, or 1xDVI and 1xHDMI connectors — but not all three at once.

It is possible that this limitation may be only for if you are trying to use EyeFinity, as that is the context in which I have seen most of the discussion. Make sure you're updated to the latest graphics drivers and such, there's a possibility that could help.

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Hmm.. Ive got the latest drivers and Ive seen plenty of people that get 3 screens out of 1 card. It has 3 ports and is detecting them all. Just display properties wont recognize more than 2 displays at any one time. So Im unable to set it up properly. I dont know what this Eyefinity is tho. – Jan Apr 1 '10 at 15:08
It could be that your card just doesn't support three displays at one time. I remember having cards with 3 connectors where only two will work at one time. – AndrejaKo Jul 9 '10 at 12:29
@Jan: Re-read his answer. He's saying you can have 3 displays but one of them will have to be connected to the "DisplayPort" (even though you have 4 ports total). So you can do TV to HDMI, monitor 1 to DVI, and monitor 2 to DisplayPort (probably with an adapter). – User Jul 18 '11 at 22:54
Yes that's right, you need one Display port connected in order to use 3 monitors, it's just how it is. Read the requirements,… – Sandeep Bansal Aug 26 '11 at 1:40
Indeed. It's because the graphics card cannot drive the clocks through all three (two DVI ports and one HDMI port) at the same time for three independent displays. One of the DVI ports and the HDMI port share the same hardware, here. Your card can support Eyefinity (which means it should support more than 2 monitor outputs) but you will need to use a display port output instead of one of the DVI ports. You likely have one or two on your card. To use your monitor with it, get an active mini-displayport to DVI adapter, and all three monitors should be detected fine. – Ben Richards Aug 26 '11 at 1:45

You can only use 2x DVI, or 1x DVI and 1x HDMI. After that you need to utilize the DisplayPort - I highly recommend using the Active Displayport adapters :)

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Hi Michael, welcome to SU. How does your answer add anything different or more than what's in nhinkle's answer from 3 years ago? – Ƭᴇcʜιᴇ007 Dec 17 '13 at 19:47

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