there are differant types of AGP Pro aswell
AGP Pro50
AGP Pro50 3.3V
AGP Pro50 1.5V
AGP Pro110
AGP Pro110 3.3V
AGP Pro110 1.5V
I had a bad issue 2 years ago when I bought a 3DLabs Wildcat 4110 and tried to stick it into a P4 board with an AGP 1.5V slot...and it was to old

...it needed 3.3 P4's are designed to only pump 1.5V Max to the AGP slot... sadly the board is still sitting here useless...
if/when ya go AGP Pro its best to spend alot of time reading before sticking one into your board...