Can't run 3 monitors at once

Hello,

I've got a setup that is running 2 ATI 5850s with dual monitors. I tried to add a 3rd monitor but when I do, I get the error message "to extend the desktop, a desktop or display must be disabled". Basically it's only letting me run 2 at a time, any 2 works.

I've got 2 monitors using the DVI??? (whatever the white port is) and one using HDMI. I have tried running all 3 from one card, and I've tried doing various combinations using both cards and I can only get 2 monitors to run.

Not doing any crazy 3d stuff, I just want 3 monitors for my desktop. Any ideas?

Hm... I imagine you are using the Windows 7 "Screen Resolution" settings.
If so, I think you have to change the settings within the ATI software, which comes with the driver.

Also did you plug in all the monitors to 1 graphics card or both of them?

Also from what I've heard, you have to use Display Port to DVI, because VGA has some problems with response.

I am using the ATI catalyst control center. For grins I tried the win7 control panel and had similar results.

I though you have to use a displayport if u want 3 monitors

Zepher said:

one monitor needs to be Display port if you are running 1 card or 2 cards in crossfire.
If you disable crossfire, you can run the HDMI monitor on one card and leave the DVI monitors on the other card.

here is a list of adapters that will allow you to run 3 screens with Crossfire enabled,
You need to use an Active Adapter,
AMD Eyefinity Validated Dongles

I was running a VGA to DP Adapter for awhile then bought an HP Monitor that has native Display Port.
HP 2310e 23" LED monitor.

Thank you, this is EXACTLY the correct fix. I had tried different monitors in different cards but with xfire enabled. Once I disabled xfire and put the HDMI in my 2nd card I was good to go.

i had the same problem with my 3 screens, i disabled crossfire and placed the hdmi in the other card. Now i can have all of them active. But when i want to create an eyefinity group with catalyst, one screen gets rejected anyway.