Only one monitor detected on pc with dual cards

I have a powerspec g212 pc that has Dual Radeon HD6790 PCI Express cards in crossfire. I have analog monitors, so I have the DVI-I adaptors that came with them, each connected to one of the DVI-I slots on each of the cards. Only one of the monitors, the one plugged into the top card, is being detected by the PC (Windows 7). What to Do?
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  1. I checked with Microcenter online chat and they said because it is cross fire, only one card will work for hooking up monitors. They said that I should be able to find an vga to DVI-D adapter for the other monitor. I will try that.
  2. Best answer
    There is no such thing as a VGA->DVI adapter.

    DVI outputs are technically "DVI-I" meaning "integrated" because they contain BOTH signals for DVI (digital) and VGA (analog). DVI cables hook only to the digital outputs, and VGA "adapters" hook up only to the analog outputs (some also contain HDMI audio on a couple pins which need an included DVI->HDMI adapter to connect to.)

    You can only hook up a VGA output directly to a VGA cable.

    *Since you have analog (VGA) monitors already just hook up your monitor or monitors directly to the VGA output.

    To be clear:
    DVI->VGA adapter is EXACTLY the same as using your VGA output. I'm just not sure how multiple monitor setup works.

    The FIRST thing I recommend to try is just use the VGA output from each card. If that doesn't work, try the DVI output on card 1 (with the VGA adapter) and the VGA adapter on card 2.

    Let me know how it goes....
  3. Just to clarify, the video cards do not have VGA connectors; they only have the following (taken from the website specs):
    1- DVI-D (Single Link)
    1- DVI-I (Dual Link
    1- Display Port
    1- HDMI

    The only thing that I currently have that will physically connect to the cards is an adapter from the VGA monitor to the DVI-I connector on the card (I just happened to have two of these laying around). This works for one of the cards but not the other. Microcenter online support says only one works because of the crossfire.

    These "old" analog monitors that I have work, but eventually I know they will have to be replaced with new monitors, but for now I would rather keep them if I can.

    If there is any way to connect the analog monitors to Dual Radeon HD6790 PCI Express cards in Crossfire™ (again taken from the online specs), then that would be my first choice.

    If there is no way to use the analog monitors in a dual setup, but I can with new monitors, then I'm open to suggestions for new monitors to purchase. This is for work using AutoCAD, and 3D software, etc. so I need decent monitors that will be as sharp as the analog monitors I am currently using (Phillips 109B 19"), and with no mouse lag. I ran into these troubles before when I replaced an analog monitor with an LCD monitor at home. I don't want to spend more of the boss's money than I need to, so I'm not looking for the best, just something comparable to what I have now.
    Any suggestions would be appreciated.

    After I wrote the above, I found an adapter online that looks like it might work on the two existing VGA monitors that I have. I would connect one monitor to Video card #1 via 'Male DVI-D to Female VGA connector' ( and the other monitor also connected to card #1 via ‘Male DVI-I to Female VGA connector' that I already have. I'd like to get some input on the possibility this working for a Dual monitor setup.
  4. I found a solution that seems to work for me. I disconnected the little piece of hardware that attaches to both cards to create the crossfire. By doing that I was able to connect the existing analog (CRT) monitors to the DVI-I inputs, one on each card, via VGA to DVI-I adaptors. No other configurations needed and the computer is still fast enough for what I am using it for (AutoCAD, Photoshop, 3D apps, etc.).
  5. Best answer selected by cinci-hal.
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