The BIOS of some newer Dell laptops (Latitude E6420/E6520/E6430/E6530/E6440/E6540/...) will override the speed you set unless you disable the BIOS control. The Fn ...

These are the folders where the bios updates will go. For each model that will be updated. Create a folder in the corresponding Make. IE, for a Dell latitde E6420. In the Source folder, there should ...