Go to
Can You Run It and put the game name in. That should give you an idea.
Note: Can you run it is not ENTIRELY accurate with its "pass" and "fail" ratings. Actually check the results.
Example: On Sims 3, the minimum requirement is 2.4Ghz Processor OR a 1.8Ghz Dual Core, Can you run it only checks for the 2.4 and returns a fail on my 2.0 Dual Core despite the fact I meet the requirements