As far as I know, Beryl isn't incompatible with specific video cards. It works just great with my on-board Intel graphics, so it should run on just about anything. Here are some other suggestions I have:
First of all, are you using the Beryl manager? It will show a jewel in the corner of your screen. If not, type beryl-manager at a console.
Also, are your graphics card drivers properly installed, with 3d acceleration? Have you tried any 3d games?
If all else fails, you may want to try installing Ubuntu instead. You said you just installed Fedora, so if you don't have anything important on that computer it may be a wise idea. Ubuntu 7.04 has a very easy way to install these effects. The Ubuntu effects do use Compiz though, which is very similar to Beryl.
If you want killer 3d effects, I have heard that the new Mandriva is the best option. I cannot vouch for it though, as I haven't tried it myself. You can find info here
. Compiz/Beryl should be enough effects for anyone though. Here
are some of my screen shots.
I hope this has helped you!