By video performance, do you mean gaming (I think not with a 800 mhz system)? Upgrading a video card for better "video-quality" is almost useless, unless your current video card doesn't support your monitors' native resolution.
You may get more options such as brightness controls or such, but that won't warrent the money for a new card.
I recently bought a 20" flat panel and I want to improve my video performance.
These are the specs on my PC:
Pentium III 800 MHz
512 MB SDRAM 100 MHz
NVidia GeForce DDR 64 MB
Would I see any noticeable improvement if I just added a mid-level video card like the ATI Radeon 9600 128 MB w/ DVI out or would the CPU/RAM require upgrading as well?
Thanks is advance,