Hey guys i need to run a max of 7 screens on extended desktop so in other words they need to be independent how do i go about doing this?
The max i can find is 6 screens on eyefinity with two AMD 7870 or 7970 in crossfire is this the max or can i get 7 screens off two AMD cards in crossfire ?
Sounds like you might be setting up a trading system.
If so, you do not need much graphics power from expensive gaming cards.
Crossfire is intended to apply the power of two graphics cards to a single gaming app.
One easy way to get a large number of displays would be to use multiple inexpensive graphics cards.
They can be about $30 each. They can use pci-e x16 slots, which are the cheapest, but pci or pcie-x4 too.
Each will drive at least two displays, but perhaps 3 if you have displayport monitors and adapters.
If your motherboard had integrated graphics, you can use their two adapters also.
If I assume that 7 screens are 1080P each, then you want to display about 14m pixels.
That will take up a lot of real estate on your desltop, or more likely your wall space.
A better, but more expensive approach might be to use 4 2560 x 1600 27" monitors, giving you 16m pixels.
The quality of those $1000 monitors is superior, and you will have better viewing angles.
In between, there are 2560 x 1440 monitors that cost about $700 each. 4 of them will total the same 14m pixels that the 7 monitors would have.
I would be inclined to go with this approach if budget permits.
And... you would only need two inexpensive graphics cards.
If you want them to be independent, I don't think you need eyefinity - as I understand it, that's for treating a group of monitors like one screen, with a game stretched across them. There are a few 6-output video cards, such as this one: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
DisplayPort 1.2 is supposed to support daisy-chaining monitors, but I'm not sure what the limit is on that, and you'd probably need to find monitors with two displayport connectors. Alternatively, I would expect two of those 6-output video cards in crossfire (or sli if there are any 6-output nvidia cards) to handle up to 12 screens, unless the OS limits that.
The new six series from Nvidia can do 4 monitors each. I "think" three of them must be in a group like Eyefinity, but you should be able to put whatever window you want in each monitor. (Only issue you'll have there is if you want it to run in full screen as it will stretch across all three.) I don't know if you can run four off of one GTX660. If you can then you'd only need two of the new six series. (not in SLI btw.)