What is a master card in crossfire? Do I already have one?

Ok, help me here. I bought the ATI X1900XTX for my Conroe system from Tiger Direct.

ATI Radeon X1900 XTX / 512MB GDDR3 / PCI Express / Dual DVI / TV Out / Crossfire Ready / Video Card
Sku No. A177-3090 - Manufacturer Part No. 100-435805

http://www.tigerdirect.com/applica [...] =A177-3090

Is this a master card? Could I simply add another ATI X1900XT and have crossfire? Do I need a special master card? Do I need any other special wires?

I don't know if I will go crossfire or wait for DX10 next year, but I need to figure out how this works. I appreciate your help.

My Rig:
Core 2 Duo X6800 Conroe (Stock Clock for Now)
Intel D975XBXLRK
Thermaltake Big Typhoon HSF
2 GB Corsair Pro PC6400 4-4-4-15
74GB 10k Raptor
ATI X1900XTX
SB Audigy 2 ZS
NEC DVD OEM Burners (x2)
Ultra X-Finity 600w SLi Certified PS
Gigabyte 3D Aurora Case

stay with ur current system.
Since u have a Core2 Extreme processor your system is future proof for atleast 3 years(as far as Cpus and everything else except the graphics cards are concerned).
In a few months Directx10 graphics cards will be released.
But the only game at the end of this year to take advantage of DirextX 10 will be CRYSIS(hopefully at the end of the year).
Directx 10 games will take another 6-8 months to surface.

Your system does not have a Crossfire Master card.
For ur system to run in Crossfire mode you have to purchase one and pair it with ur current graphics card.
This is unlike Nvidia SLI in which two similar cards are required.
in Crossfire u need a Crossfire master card and another card of the same chipset.

Thats all.
msg me for further details.