Mac Pro 2010 Graphics Expansion

A video splitter may work to get two from one.

You can also install another video card.

Your graphics card like has at least two outputs and can support two monitors/projectors but it depends upon the input for the monitors/projectors.

You can get USB video adopter

http://www.kensington.com/kensington/us/us/p/1505/K33974AM/universal-multi-displ ay-adapter.aspx#.UxSD9_mwKBo

and a there is:

http://www.matrox.com/graphics/en/products/gxm/dh2go/digital_me/

http://www.matrox.com/graphics/en/products/gxm/th2go/digital_se/

Do you want the same picture on 5 projectors?

or 1/5 of the total picture on each of 5 projectors sitting side-by-side to make a really big picture?

More graphics cards and/or USB adopters.

What is input for the projector?

Maybe also use a splitter.

the "triple head to go" solutions take a display output and split it up for multiple screens. They won't stretch to five screens. You will need multiple "real" display adapter cards and/or USB screen adapters (said to be "slow" to refresh).

Is this a rapidly-moving picture or something more like a PowerPoint presentation? If rapidly-moving, you may need to skip the USB adapters and go straight to multiple "real" display adapters.

The 5770 was the default graphics card for the 2010 model. It requires only One aux power connector and has one (up to) Dual-Link DVI-I. VGA can be derived with a stunt cable adapter. It also has two Mini Displayports -- look carefully, they don't look like much but can be adapted to many other display protocols. There is a limit to how many "legacy" conversion you can ask the card to do before it starts dropping displays -- ACTIVE adapters may be needed for some "legacy" adapters.

From there you could add another 5770 in the second slot, or a card like the GT120 that has only two more ports but does not need an Aux connector.

The mac supports a mode called "extended desktop" which creates a virtual desktop across multiple displays, like this:

you drag the icons in this window (both horizontally and vertically) until they represent the physical arrangement of displays on your bench. Then the mouse moves freely across the boundary between displays. You can drag a window across to a different display, or park it across one or several boundaries and it will update "the right way".

Since this feature is supported by Mac OS X, it works in all well-behaved Mac Applications without additional fiddling, except in cases where the developer had deliberately precluded it, such as in some versions of iMovie.