[CentOS] CPU Upgrade

Hi all;

I have a Dell 2900 with a single Quad core chip and an expansion slot for a 
second Quad core chip.

I have CentOS 5.4 installed on the server now. If I add the second Quad core 
chip do I need to change anything per the install? Do I have to re-install the 
OS? Or will CentOS simply see the second chip once I reboot and just work?

Thanks in advance