I think that it could limit your performance. I also think you should be around the 2800+ to 3200+ range. As far as the AGP speed goes, its not going to matter much unless you run games at high details, which might put the AGP 4x bus under load, but since your card is midrange, and it can't run at uber-high resolutions (i.e. 1600x1200) playably, you shouldn't have to worry.