Performance hit from two screens?

If so, what kind of difference does it make?

I have an X1900xtx

Thanks in advance.

With my 6800Ultra, I notice a performance difference in some games, ones that I can think of as of late, are the prince of persia games, I get a noticable performance increase by turning off my second monitor. Also for me, I get better video playback with just one monitor. Not like thats an issue with your ATI card.

My dad used to run a Nvidia 6800, and when he had both monitors hooked up, there would be a performance hit. For him, he had a HUGE performance hit. untill he went into the bios and noticed that the defult Display adaptor was set to PCI. Once he changed it to AGP, That fixed alot of his problems.

After that, the performance hit was ALOT lower. But there was still one. i can't tell you how many FPS's he lost. and he got that hit from usually playing Guildwars, or City of heroe's, and his 2nd monitor usually running firefox so he can browse his guild's Forums.

On my 9600 I ran a monitor and TV out cable, I didnt notice too much BUT I only used the TV out every now and then for some videos..