What is the best way to enable the use of triple monitors?

Question

I'd like to use three screens. I've looked on Google and found a lot of different and contradicting answers, so I decided to post a question.

What I have now: three screens, and an NVIDIA GeForce GTX 460 with 2 DVI ports and 1 HDMI port. I think that just linking the HDMI port to another screen won't work, and I've found a lot of solutions, but I'd like to hear the best and cheapest way to get it done.

I also have an old NVIDIA GeForce 8600 GT. Could I use that to send the signal, but let the 460 GTX do any calculations? Or perhaps it's possible to let Windows/the card think the three screens are one screen, so it's only really rendering one big image that can be split somehow?

Answer 1

You need to use an additional video card to get the triple monitor setup working. Additionally, if you wanted to use SLI/Crossfire in this setup, you would have to check Nvidia's website to see if triple monitors are supported (e.g. I had 2 x 8800 GT's in SLI, and had to disable SLI to get triple monitors to work - this does work with some newer Nvidia cards however). See this page for more details.

Using two video cards in non-SLI is a completely different story, and quite possible with the 8600 GT you mentioned. My recommendation is to use your one center monitor as your "main" monitor (and have the 460 GTX be that monitor's hardware acceleration), and plug the other two monitors into the 8600 GT. That way, 3D applications that output to your main display won't take a performance hit (those running on the additional monitors will - you might want to put one of them back on the main 460 GTX if you need something else hardware accelerated).

The core requirement from Nvidia's website to use an additional video card to drive an additional monitor is:

Additional monitors (up to 6 monitors total enabled) may be enabled by using either a motherboard GPU and/or a PhysX capable graphics card (GeForce 8 series or higher with at least 256MB of memory) that does not have the same GPU as those that are SLI enabled. More information regarding multi-monitor in SLI can be found here.

The above information applies wether or not you use SLI.

Answer 2

If you have on-board video-card, which almost every computer has now, since the new CPU's have a built-in graphics card on the chip...

Use that for one of your side monitors. (Since that will be one of the slower ones.) You may have to ENABLE ONBOARD VIDEO in your BIOS, if it is not seen. Some computer builders turn it off, to stop confusion, due to using external PCIe/AGP cards for video-out.

Then use the other two for the remaining monitors, from your graphics-card.

The issue with HDMI/DVI-#1/DVI-#2 on your card, may be that it was intended to be one or the other... HDMI/DVI-#2 or DVI-#1/DVI-#2, not HDMI/DVI-#1/DVI-#2

Unless it says "3-view" or "2+ monitors", etc... (I have Hydra-vision, so mine has 2 additional mini-DVI, which outputs up to 4 DVI connections per mini-DVI port. There is a special cable needed for that, which I don't have. However, I can still only use one of the mini-DVI port, if I use either HDMI or DVI for the other connections.)

Windows doesn't care what video-cards are used for output. It has direct-access to the RAM and PCIe busses, in the I3-I7 series and higher CPU's. (Which is why memory speed and bus-speeds are tied to CPU speeds. Otherwise the data doesn't align, and can't be read.)

https://www.laptopmag.com/articles/intel-hd-graphics-comparison

Whatever card you have, that is NOT the one built-in to the CPU, will be the controlling card. It just sends the "drawn images" to the other two ports. That requires almost no slow-downs, as the rendered image is low in data. Your internal CPU graphics-card will not be doing any actual processing, except spitting-out the image it was just sent, to the on-board port chip.

The on-board port may be near your USB connections. Often just below them, against the tower-case edge. That may be limited to only HDMI, or DVI, or it may have both, but only one will work. For the same reason as with the video-card... It is one or the other, not split-view. (It was done that way so you wouldn't have to buy a spotty or laggy HDMI->DVI converter, or the other way around.)

http://www.pcstats.com/articleimages/201011/ecsH67H2_d4.jpg

Your video-card software will see all three screens and give you control from those settings, for all three screens. However, that one screen, controlled by your CPU, will also have an individual set of display drivers too. Those will only control that one screen. (Used to adjust things like fit to screen, orientation, etc...)