M6600 i5 memory upgrade

I'am getting a M6600 laptop with only 4GB (2gb x2) 1333mhz memory. It has the i5-2540M cpu. Will 1600mhz casL 9 work plug in play? Or will it only run at 1333, and can I changed the timings to less? Also will the extra 2 dimm slots under the keyboard work if I have the i5 or not? I'm looking to get 8GB(4GB x 2) I dont think I want to put 8GB(2gb x 4).

Any info would be appreciated. Thanks.

 

1600 MHz should work. You cannot use the slots under the keyboard unless you have a 4-core CPU.

 

Thanks, I will go with 1600mhz then. Is weird on Dell's site you can't configure 1600mhz mem with the i5. Says its not compatable. Maybe a Dell scheme to get you to upgrade to a i7?