I have a GTX 275 video card with 2 DVI ports. I already run 2 monitors, but I've seen cables that plug into one DVI port and split into 2 more connectors.

Is there some special trick to getting this to work with my card so I could have up to 4 monitors running? I don't really want to buy the adapter until I know that it will work (or not work as it may be).

11 Answers 11


Unfortunately a splitter will just mirror the display on 2 monitors. You will need something like the dualhead2go devices from Matrox to do what you're talking about.


It is quite possible that the cables you saw were not plugging into a normal DVI port, but into a DMS-59 port (especially if you saw it on a Dell). DVI and DMS-59 look quite similar unless you look close enough, but the DMS-59 connector has in fact the equivalent of two full DVI connectors, and thus needs the split cable (you cannot directly plug a DVI cable into a DMS-59 port; it will not fit).

These ports are normally used so a smaller card can be used for two DVI or VGA monitors (Dell likes using half-height cards on some models).

  • 3
    +1 For explaining the difference between DVI and DMS-59
    – Thrawn
    Commented Apr 9, 2013 at 22:48

Your card has two Dual Link DVI connectors (see Wikipedia page here). However, a Dual Link DVI connector cannot output two independent displays -- it is used for driving higher-resolution monitors (2560 × 1600 as opposed to 1920 × 1200 on Single Link DVI).


You cannot split a single DVI port to two monitors. I have seen splitters on video cards (like the Dell I am on now), but it's not connected to a DVI (though it looks roughly the same size), but another style of connector to two DVI's. I do recall seeing a splitter from a DVI to two DVI's but it wasn't used for two monitors but for a monitor which required two DVI inputs.


You can use a DVI spitter and extend the desktop. I have been doing it with a Radion 6xx half space card for years on a Dell optiplex. But now that I had to reformat this box due to virus, I now can only get the monitor to clone. I failed to bookmark a page I found about 2 years ago with the solution.

I am vague on memory on what needs to be done but the problem is in the monitor INF that windows generates automaticall where it is looking for vga instead of DMI because I have an onboar vga port. Even though an external DMI card is installed which automatically disables the onboard VGA port, windows is still looking for VGA.

The trick was a process of uninstalling the monitor entry in device manager and be sure delete the driver too when prompted then let the system boot to write a new monitor INF. But there was a specific procedure to follow to get this to work. Once I figure it out, I wil post to this forum.


I have an iMac and HP 2009m monitor. I just installed the mini DVI cable to VGA from imac to HP monitor. I didn't have to make any change on Mac side every thing is working perfectly. On Windows 7 I was having some issue where I have the duplicate image and could really use the mouse interdependently from a monitor to the other. Here is the solution:

In Windows 7:

  • Right click your Desktop
  • Click Screen resolution
  • Change the appearance of your desktop
  • Display, I choose the imac Monitor Color LCD)
  • Resolution, 1980 8 1080 depends what urs is.
  • Orientation: Landscape
  • Multiple Displays: Extend these displays

Click Apply Ok..Done.

  • 2
    Comment by @Sam: A quicker way on Windows 7 is to just press the "Windows key + P" and scroll through the modes.
    – Ivo Flipse
    Commented Jan 15, 2011 at 5:41

You actually can split the DIV-I to two monitors. We do it for the wyse system here all the time. You can use the 920302-02L to split the DVI-I to DVI-D and VGA. there is a setting in the wise that we trun on for this to work. However You can not use a DVI-D to VGA converter to get output to two VGA computer all it is going to do is clone the screen. I am guessing because you can only send one analog and one digital not two analogs. Good luck.


In my case I bought a used half space Radion X600 series DVI card with a Y DVI splitter from Ebay for my Optiplex that is running Vista. Vista ends up installing ATI Radion X300/x550/x1050 driver.

I also installed the ATI Catalyst Control Center.

Problem will be that extended monitor config will work but not after reboot or after computer is logged off until I FIX...

Go into device manager, uninstall the two monitor entries and also check box to delete the driver which will appear after uninstalling the first monitor entry. Once both monitors are uninstalled the monitor entry in device manager is gone.

Shut down the computer, restart...computer should come up with both monitors working but cloned by default. Configure the displays for extended desktop. Once it is working as desired, go into profile manager, delete any existing profile and create a new profile, name it...save it...activate and close. Reboot the box to confirm that the configuration sticks. Problem solved.


I would recommend an active DVI Splitter not a Y cable. These Y cables don't work as advertised. Also, a DVI Splitter enables you to display the same image on multiple monitors.


If you are looking to display the same image on multiple DVI monitors you can use a DVI Splitter. I have used DVI-SPL-2 in the past and they work well. If not , the only option is to get a quad video card with DVI outputs.


If you are looking to display different images on all 4 monitors you will need additional video cards. All a splitter does is display the same image on multiple monitors that is it mirrors the image. If you are looking to display the same image on multiple monitors you can use a DVI Splitter, but it is recommended to use a powered splitter. These Y cables are a waste of time and money as they don't work well and degrade the video quality.

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