Hi there.
Firstly, are you looking to game across the three monitors? If so then what I have to say may be very important.
Sell the GTX 580 and get a 7970.
Here are my reasons why I would do that, speaking of course from experience.
Firstly two Nvidia cards mean two times the power consumption and two times the heat. I've yet to meet either a motherboard or case that can be set up as such with air cooling. Of course by that I mean "get single card temps out of two", it just doesn't happen.
If you are prepared to live with the extra noise and heat* and power consumption then the next part becomes even more important.
* as soon as you connect two monitors to an Nvidia card it automatically goes under full load. This means that even a single card will now idle in the high 40s and low 50s before you even start. Your adaptive performance goes for a burton and you get hot. Then you add another card to that, and it gets hotter.
But worst of all, and what I just could not live with (I had resigned myself to sitting in a Turkish Bath beforehand) is the software issues and horrid layout of the monitors.
Right. SLI = hmmm.. Maybe, if you really want to.
Surround = hmmmm. Maybe, if you really want to.
SLI + Surround = No. Just.No.
Firstly as you know SLI relies on software. Software meaning drivers, and also game support. Both of which are so so IMO, and if you don't mind a wait then hey, I guess if you were happy with that then all's the good.
However. Surround = software based. Again, you will need to rely on Nvidia to keep you working and up to date. And, they don't. At all.
Here are my findings from running SLI with three monitors.
1. There is no such way in Windows 7 to see three displays seperately and then put them together. So, because of this, the drivers are a hack. They basically force the WHDM driver in Windows (I'm sure that's what it was called) to see the three monitors as two monitors. When you go to your desktop resolution settings in Windows this is what you will see, two monitors patched in the middle.
Because of that the options to change how the desktop is laid out are 0.
Your start bar will be all the way to the left, and your icons and volume and so on are all the way to the right.
2. Given the above, software simply does not understand the above. That means when you open say, Chrome, or Firefox, or a folder and maximise it the folder stretches across all three screens. Meaning you need to turn your mouse into a schizophrenic out patient in order to navigate.
None of that would be a problem if you could "snap to grid" your windows. But you can't. So as soon as you minimise you then have to resize manually onto the middle screen (or the side ones and get a lovely neck ache). However, your programs will not memorise those settings. Meaning, every single last time you open one up you have to sit and bugger about resizing it.
I found, due to the above, that I could not live with three screens as my desktop. In the end I built a second PC to play surround on.
3. Nvidia drivers are absolutely crap for surround. It's quite clear that Nvidia like to sell you two cards for the option of surround, and thus have lots of information about surround itself on their website and what cards you need to do it with (which of course they would, it boosts sales).
However, sadly, they don't give a flying crap about you or your wishes to play games over three monitors, so as driver revisions go they gleefully break things each time meaning you will be chasing your tail trying to find the perfect driver to stop the problems most have.
Those problems are.
1. Surround will not see your monitor resolutions or refresh rates properly.
That means you will then have to do it via the Windows desktop resolution part. However, that doesn't come without problems, so let's lead onto -
2. In most of the drivers I tried there were horrible refresh delays in drawing the three displays. What I mean is Aero would disable when you opened say, Chrome, and then take a couple of seconds to come back on. In a couple of drivers Aero broke completely and nothing I tried got it back.
3. The games. Oh dear the games
When you start a race on say, Dirt 3, it takes a couple of seconds it seems for the graphics to build and the screens to be ready. This is fine if you're playing single player, but if you're racing against a friend you've lost before you even started.
So, given all of the above it will come as no surprise that I broke out the polyfilla and took the monitors off the wall.
Apparently the 7000 series Radeons solve all of this, allowing you to use your middle display as the main one with all of your main icons, windows button and small icons and volume controls etc with the side ones being the extensions.
But I won't say for 100% if they do, I'm just certain I saw AMD bragging about it a few weeks ago and showing pics in the lead up to the 7970 release.
I hope that helps. And sorry if it's a little in depth for you, I just firmly believe that honest advice is good advice.
Cheers.
especially when i'll be messing with battlefield 3 @ 5760x1080 res!