Huge FPS Drop issue in Alienware m14x R2

I'm experiencing a huge FPS drop when i play games on my laptop.
I called the DELL Technical Support (India) but they were unable to troubleshoot the problem and they just replaced my motherboard which was not necessary (and the problem still persists).

I've tried almost everything,
- Restoring my machine
- A clean format
- Installing the drivers in the proper sequence (Recommended ones first)
- Added every game i play to the Optimus NVIDIA control panel.
- Using the latest NVIDIA GeForce Experience to get the optimum settings for every game installed on my machine.
-All my drivers, BIOS version (A 12) and everything is up to date.

What i found was ----
When i run Alien-Autopsy  then My Machine passes the "High Stress Gaming Test"
But the FPS goes to 5-6 FPS from 55-60 FPS during the "Wireframe Shader Rendering Test" & "Wireframe Line Test" for both Intel HD Graphics 4000
& NVIDIA GeForce GT 650M. Everything was so good when i purchased M14x. Both the tests that i mentioned above ran smoothly at 50-60 FPS.
I cannot understand what to do with this information i obtained. I really need your help.
My Rig :- 
Intel i7-3630QM, 2.40GHz
NVIDIA GeForce GT 650M
RAM - 6GB
OS - Windows 8 Single Language 

Regards-
Manvendr