Adding a 2nd video card

[sigmend]

I am looking to add a Radeon 7000 Mac Edition to my PowerMac G5 but I am not sure if it will work correctly.
If I add a 7000, will my primary video card loose any performance? Will it disable some features to match the 2nd one?
I know I am pretty poorly worded, so go ahead and ask for clarifications if needed.
The only real game I play is World Of Warcraft. If I loose any performance, I don't think the game will be very playable.

Info:
Dual 2Ghz G5 Rev A
Few gigs of memory
Not sure the video card, reported as 9600 Pro by system profiler, but I don't think that makes sense. It is the stock card in the Dual 2 Rev A systems.
Right now I have two displays on my video card. A 23" Cinema is on ADC, 17" 170MP on a DVI->VGA adapter. I want to buy another 23" cinema, put it on the primary, then drop the 170MP onto the R7000.

 

[Black Morty Rackham]

If I add a 7000, will my primary video card loose any performance? Will it disable some features to match the 2nd one?

No.

The only real game I play is World Of Warcraft. If I loose any performance, I don't think the game will be very playable.

Unless you play the game on a monitor connected to the R7000, you won't lose performance.

Basically, the Radeon 9600 renders to the displays connected to it, while the the Radeon 7000 renders to the displays connected to it. At least I think this is how it works...