Should be fine, the requirements for Q4 from ID software :
Minimum System Requirements
P4 1.5GHz CPU (or equivalent).
384MB of RAM.
64MB graphics card.
Lowest supported GPU is a GeForce 4 MX (worse than GeForce 3).
Supported cards:
GF 4 MX.
GF 3.
GF 4.
GF FX (and higher).
Radeon 8500s, 9000s and higher.