Will this configuration work for crysis and such games?

4 Gig RAM is definitely a high amount, it should be more then enough for most PC games, though of course turning down the settings a little bit is always worth it rather then spending another 100 + Dollars in getting a slightly better RAM. If you really want to make sure, im sure you can visit the home page of the game you want to play, and check out the required specs, you can also join their forum and display this information for direct answers on that specific game.