Water cooling radiator: suck or blow?

[wallabing]

Which would be better for heat dissapation?

1. Mounting a fan behind a radiator and letting air get sucked through the radiator

or

2. Mounting a fan in front of the radiator and letting air blow into the radiator.

Any help appreciated

 

[Rik]

Either should work well, but getting the air blowing in should be the more efficient!!!!!