Unless you're playing games, it won't make a lick of difference.
You could buy a cheep X300 and get the same video encoding performance as an X850XT, the video card does not assist in encoding video...
<b>Geforce <font color=red>6800 Ultra</b></font color=red>
<b>AthlonXP <font color=red>~3300+</b></font color=red> <i>(Barton 2500+ o/c 412 FSB @ 2266 Mhz)</i>
<b>3dMark05: <font color=red>5,275</b>