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Cannot enable more than 2 monitors on HD 5970

Just got an Alienware AW2310t monitor today to add to my two LG W2252TQ's.

Although irrelevant, I've paced the AW monitor between the 2 LG's.

OS: W7
CPU: i5 750
GFX: Sapphire HD 5970
RAM: 4GB 1600Mhz

The LG's are both connected via DVI while the AW is connected through DVI via DP.

My problem is that I can only display 2 monitors at any one time... (All combinations attempted, all monitors in working order)

From my understanding and research of the subject this should not be the case with the setup that I have.

I have tried a few obvious things like having same resolutions @ 1680*1050 (AW defaults to 1900*1200, LG 1680*1050), while there a few simliar problems out there I can't seem to put find the answer, can anyone tell me what I'm overlooking or what the cause of my problem is?

13 answers Last reply Best Answer
More about cannot enable monitors 5970
  1. Have you tried "extending" the desktop?

    Also go Control Panel\Appearance and Personalization\Display\Screen Resolution there should be a display of all three monitors, and also check the drop down bar next to display....
  2. Is your DP-DVI converter an active one? If ur using a passive one u wont be able to use all 3 monitors.
  3. Yeah I've tried extending it, aswell as duplicating from the other 2 monitors. But no matter what I do 'it' insists on only being able to run 2 monitors at one time.

    Oh, and FYI. Initially using the DP -> DVI adapater for the new AW 120hz monitor resulted in not being able to access the 120hz 'feature'. Thus I'm now linking the AW monitor with 'true DVI' (no DP adapter). Therefore one of the LG's is true DVI while the other is DP -> DVI.
  4. The placing of the adapter aint a big deal. ive seen some ppl say it should be on the middle screen but im using mine on the left screen and its working fine.

    But since u didnt answer my question i guess ur adapter is active?

    it might be a problem with that theres 2 different resolutions. Eyefinity only supports same resolution on all 3 monitors.
  5. @Snoogiloo: This could be a hole in my understanding, could you explain the difference please? I have a feeling what it is but I and others would be best off if you explained it :)

    That is between passive and '...non passive'
  6. Best answer
    An active adapter?
    I cant explain it very good tbh :P But as i have understood the normal 5k series cards can give an individual signal to 2 monitors, and when using an active adapter it will be able to handle 3 monitors instead of 2.

    Can you link to the adapter ur using? that way i can say if its active or passive :)

    EDIT: The difference between active and passive is simple.
    Passive adapters are merely a cable to go from displayport to DVI/HDMI/VGA/w.e. The video card detects the monitor as such, and outputs the required signal (DVI/HDMI/VGA). This does require one of the two aformentioned clocks, hence why they do not work with eyefinity cards.
    Active adapters, on the other hand recieve a displayport signal from the video card, and convert it to DVI/HDMI/VGA. They will always have some sort of onboard DAC or video converter chip which they use to convert the dp signal. Lately, most everyone has been referring the DAC ones (which are the converters that go DP->VGA) as 'passive.' This is not the case.

    (Copied from a thread at

    99% sure that's the one, bought it today when I got the monitor since I had done a little research about my 5970 before hand. Although I hadn't run across this problem...
  8. Thats a passive adapter im afraid :/
    Thats the kinda adapter ur looking for. Thats a DL-DVI adapter, theres SL-DVI adapter out there too thats a little cheaper but can only handle resolutions up to 1920x1200, but thats no problem in ur case.
    Unfortunately i didnt find any SL-DVI adapters on that site. When buying an adapter u should look if it says Active, if it dont its a passive one.

    If theres any other website u are able to buy from u can link that and i will check for a SL adapter for u :)

    The help is much apprecaited :) I have a fair idea now but if you're able to confirm which one(s) of those will work that would be great.
  10. Normal DP:

    Mini DP:

    Thats SL ones even tho they say its DL ones, donno where they got that from ^^ DL ones should be able to handle higher resolutions and at 1920x1200 it should be able to handle higher refreshrate.

    Just pick if its Mini DP or normal DP on ur card :)
  11. Best answer selected by serialz.
  12. Awesome, once again thanks for all the help Snoog :D

    As a sidenote to anyone that might stumble upon this (although feel free to correct me if I'm wrong); if you're using Display Port to connect to a 120Hz monitor then you'll most likely only be able hit a maximum of 60Hz. This is of course a problem with the HD 5970 as while you have 2 DVI's you're stuck having to use a Display Port. Hence a single HD 5970 can only output 120Hz to 2 monitors and the other on the DP will be stuck @ 60Hz.
  13. This topic has been closed by Mousemonkey
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