DVI vs HDMI

hdmi is essentially a dvi cable with a different connector. they share the same base level performance.

only "substantial" difference is hdmi can carry audio, and some newer versions of hdmi (v1.3+ or so) might support a few things dvi doesnt, like integrated ethernet or deep color (higher color depth <-- your software and hardware must both support a high color depth [30bit+] for this to work properly though).

or if you want to display a resolution above 1920x1080 or 1920x1200, youll need a dual-link dvi cable or an hdmi cable v1.4 or higher or some crap.

dvi can get a bit complicated, too - theres dvi-a, dvi-i, dvi-d... choosing the wrong one can impact performance, or have it not work altogether.

so basically, youre probably better off with hdmi, even if you dont want to use hdmi for audio. if you have both a dvi and a hdmi cable however, I'd test using both. sometimes monitors/TVs process different inputs differently, yielding different performance.

quote The Slayer

You will need a graphics card that has 3-4 video outputs to support 3-4 monitors. It doesnt matter what outputs they have as you can use which ever you want. For example, many AMD video cards have two DVI ports, a HDMI port and a Display Port. You can use all 4 connectors on 4 different monitors at the same time to show a different image on each one.

I was looking at a graphics card that could use up to six monitors but would that only be possible by linking multiple graphics cards and using all the ports individually? I couldn't use something like this though, correct? I never realized it until I just looked that up but it says it transmits the same picture to two monitors. If I wanted two or more independent monitors that are extensions of my desktop I couldn't just use that splitter I'm guessing.

Right now I only have two monitors but I need to upgrade one of them. It works but the quality isn't very good. Once I have more money I plan on getting rid of that one and getting two new ones.
The left and right monitors would be the new ones and my current monitor would be in the center tilted 90*.