Edit: thread title has been updated because the BIOS and EC issues apply to all Alienware 18 systems, not just those with a 4930MX CPU. This subject has been discussed in numerous threads for the Alienware 18. Here are some links to other threads as a cross-reference:
How to Overclock the Alienware 18 and Haswell CPU (or actually have it run full stock Turbo Speed)
How to Overclock the Alienware 18 and Haswell CPU (or actually have it run full stock Turbo Speed)