Depends if you meet the minimum system requirements.
Codemasters reveals the specs for the PC version of their soon-to-be-released racing game, DiRT 3:
Minimum System Requirements
OS: WinXP, Vista or Win7
CPU: AMD Athlon 64 X2 2,8 GHz, Intel Pentium D 2.8 GHz
RAM: 2 GB
HDD: 15 GByte
Gfx Card: AMD Radeon HD 2000 256 MB, Geforce 8000 Series 256 MB
Recommended System Requirements
DirectX 11
OS: Vista or Win7
CPU: AMD Phenom II or Intel Core i7
RAM: 3 GB
Gfx Card: AMD Radeon HD 6000 Series
Just because you meet the minimum requirements does not mean the game will run smoothly on low details.