Ouch, that's a somewhat old card..well Fedora 5 does not (I wonder if any distribution does) come with 3d-accelarated drivers; it includes the driver "ati" that probably works for your card, but that's software rendering. For hardware rendering, you'll need 3rd-party non-opensource drivers; ATI has fglrx-drivers but they work for radeon 8500 and newer only (meaning, I haven't heard of anyone who would have got them work with cards below 8500).
But, again there is hope
I don't know how much but you can find out. The MESA rendering offers 3d drivers that could work with your card. They're not as good as fglrx is, but then again, probably the only way for your card. nVidia cards work better with Linux, that's my opinion..ATI's drivers are awful (I have 9200SE and just got lucky to get 3d-accel with fglrx; though then my screen went dead bright, and nobody knows why).
But google for the MESA project and read more about there, find out if your card could do with the drivers and so on. There is more help available..