I'm looking to do a 5 monitor setup on my new computer build and was wondering what graphics setup you guys are using to achieve more than 3 monitors. Many people have said about DisplayPort but how much strain will go on the videocard using 5 monitors for it?

I have not had more than 3 monitors at one time in Windows, but I could have had more - I do not recall which video cards I was running, but they were at the time about $450 each.  WAY overkill, as far as I can tell.
 
When 1 of the cards bit the dust after only 6 months, I get rid of both of them and dropped to 2 monitors, both running off the on-board graphics of my computer.
 
I have been running 2 monitors off the on-board graphics ever since, and don't think I will ever again spend that kind of money on video cards.  I just don't think it is needed, other than simply to provide enough ports to plug the monitors in.
 
I currently use an HDMI cable for one monitor, and for the other it is a simple VGA cable.  I have ZERO display problems, and no performance issues either.
 
SOOOO, even though the above does not directly answer your question, it DOES put forth a notion that perhaps you do not need to spend giant bunches of money on video cards for using Sonar.
 
To the best of my knowledge, all you need is 2 or possibly 3 cards to have enough video connections available for the number of monitors you want to run.
 
Perhaps someone with more explicit knowledge can chime in on this for you.  
 
Bob Bone
 

My setup is a bit unusual, and also a bit retro. I have four old Dell monitors (19-inch, 5:4 ratio) connected to three old Matrox graphics cards. I'm not necessarily recommending such a setup, but it works well for me and the image quality is great. The combined total amount of RAM in the three card is only 512MB, but that is not a problem for running Sonar.
 

Previously I was using Radeon HD 5450 (driving 2 monitors) and NVIDIA 210 (driving 1 monitor, but I think it can do two as well) for a total of 3 monitors. All fan less cards and all monitors running at 1080p. I wasn't planning for a mix of different cards, but just for trying out to support the third monitor, as I already have the other card. And both cards worked well.
 
Recently the NVIDIA 210 card was damaged due to lightning which damaged one of the monitor as well. I'm now planning for a 4 or 5 monitors setup, so I'll be looking for another fan less card that supports 3 monitors, to add to the existing Radeon HD 5450.
 
Regarding the display port.. I just use a converter to convert it to HDMI. I don't think my setup is capable for games but for Sonar there is no issue.

For 2D? Little strain. Even integrated Intel cards can drive 3 monitors these days. Really the issue is getting enough output lines/TDMS transmitters to drive all the displays.
 
If you want 5 monitors on one card, there aren't a whole lot of choices. AMD has a few cards that have 6 mini-displayport outs that can do all 6 at once, Matrox makes a bunch of different 6 and 8 monitor cards.
 
What I generally set up when someone wants that many monitors is a multi card solution though. Cheaper and easier. Use the integrated card to drive two, get a addon GPU to drive the other three.
 
If you make sure the monitors you buy support both DVI and Displayport in, you should have no issues finding cards to drive them. Most cards supports one or two monitors via DVI (or sometimes HDMI which is the same thing electrically) and then the rest via DP.
 
Just make sure the card you get supports the number of outputs you need. Some cards have more physical connectors than display lines. Like I have a GTX 980 with 2 DVI, 3 DP and 1 HDMI connections but 4 monitors is all you get at one time, the multiple connections are for your convenience in what kind of hookup you use. Also note that most cards, other than Matrox, only support 2 displays on DVI or VGA the rest have to be DP and the cheapie passive converters don't work, you need a more expensive active one.

I'm using a NVS450 from Nvidia, which is fanless. It can drive up to 4 monitors, but AFAIK you can have several NVS cards so its just to buy one more :)

Sorry to hijack this thread momentarily but I have a question raised by something said above.  I am running an ASUS P8H77 MoB and using a Nvidia 210 Graphics card driving 2 27" monitors, am I correct in thinking that I could also run a third monitor off the on board graphics ports, there are four physical ports, a display port, and HDMI, a Digital and an VGA 15 pin on the back plate of the MoB.
 
Thanks for letting me have a little moment of your threads time.

You'll need to read the MOBO manual and it will tell you what your on board video is capable of. I just bought a GigabyteGA Z97X and it can do 2 with no problem and a third if you do something in the bios. It has 4 types of connections but as said above you can't always use all the connections at the same time

Thanks JohnnyV I will read the manual and also see if any other have any insights.

Sorry this is a bit off topic, but have any of you ever experimented with having a vertical monitor? I currently have 2 regular 24" monitors, and it's great... But when I get my next computer, I was thinking about putting a tall, vertical monitor in the middle for 3 total. I'm assuming that Windows 7 or 8 (or maybe 10 by the time I really get around to a new computer) would support this unusual setup... And it just seems like an awesome way to see a lot more tracks at once. Any thoughts?