Which cards support up to 12 monitors?

I have 3, 23" HD monitors, but I don't play games all that much.

I would like to add anywhere from 3-9 cheaper monitors than what I have now, maybe like 22" AOC monitors for $100 each, but 1920x1080 capable.

Purpose is for monitoring stock markets.

My system specs is as follows:

-i2600k 4.5 ghz
-vertex3 ssd
-Radeon HD 5850 1GB
-650w XFX PSU

Question: What would be the most cost-effective way to go about this? My friend told me that it wasn't as simple as adding a second identical card for 3 more monitors, and that I need to buy a new $500-1000 graphics card

Question2: If I decide to stop at 6 monitors, would I be able to run two radeon 5850's separately, with a shared desktop? Someone told me I would run into issues with this but I didn't bother to ask what they meant.

would i be able to use this with my current card? They would run separately?

ouch.. i would have thought adapters would be like $5-10

could I just get another 5850 and run 6 monitors with 2 cards?

because iirc from benchmarks, the 6870 is comparable to the 5850 and I don't want to spend that much on a new card that doesn't offer any improvement.

A 5850 will run up to 3 monitors, I've done it. You don't need or want an identical card for crossfire because you'd still be limited to 3 monitors. Your best bet would be to buy an eyefinity card that supports 6 on it's own, then you could run the two cards in tandem (not crossfire) with 9 monitors.

There aren't a lot of 6 monitor cards out there, though, and they are pricey. I remember there was an Eyefinity 5850 and 5870. For 3 monitors just running desktop/2D stuff, even a 6750 or 6670 should be fine. If you plan to watch a movie or game a little just run it off the 5850.

http://www.newegg.com/Product/Prod [...] 6814150574

This card has five ports, and is only $120.

As others have stated, you don't need or want another 5850. Your cards only have to be the same when you're using crossfire. Crossfire treats 2 or more cards as a single card for increased performance, but you only get to use the displays from 1 card, and you don't need a 5850 to drive monitors.

This XFX hd6770 looks like it supports 5 display port monitors. If your monitors don't have display ports, you'll need active adapters.

Have you checked how many extra PCI express slots your motherboard has?

^Right, but looking at crossfire 5850 power usage when you are considering a 5850 + 6770 (or less) isn't very representative. 650W will be plenty for what you are considering. Also bear in mind those power charts are "at the wall" so if you factor in efficiencies and such, let's say they were using an 85% efficient PSU, then the actual PC power usage is only 468W.

2 of these and you are all set!
http://www.newegg.com/Product/Prod [...] 6814195102