AGP Card in wrong AGP slot?

I have a Dell Optiplex GX150 with 4MB of video RAM, and my ATi Radeon (Bought it used from a freind, unknown model) fits in the slot where the VRAM is on the motherboard, but since i dont know the model number of the card [it says (right above blue heatsink) "ATi-RADEON RV100"]. It has 4 chips along the side furthest from the I/O panel, and it has a yellow video connector, an S- Video port, and a VGA port. I believe it is a Radeon 7200. Anyway, back to the question. what would happen if i put this card in and its an 8x AGP card? my mobo has a 4x slot. Whats the worst that would happen if the card and the slot were incompatible?

 

The Card should run fine, just at 4x instead of 8x.
But to be sure, check that the operating voltage under 4x for the card is compatible with the voltage supplied by the 4x AGP slot on the MOBO. You will need to check documentation for both MOBO and the 8x AGP card.