I just got off the phone with support; however, I don't trust they're answer of the maximum allowed ram on my m11x. Would I be able to put two 8GBs sticks in my m11x without having issues. He said it would be fine. I can provide the service number as well. Here are the specs of my laptop as well.

Item Description:
-- Alienware M11x R2 Laptop Genuine Windows 7 Home Premium
-- Alienware M11x R2 Laptop
-- Keyboard on Notebook
-- 320 GB SATA Hard Drive (7200 RPM)
-- Shipping Material
-- Genuine Windows 7 Home Premium
-- Certified Refurbished
-- Information
-- Software
-- Information
-- Soft Touch Stealth Black
-- 8 Cell Primary Battery
-- 11.6 inch High Definition WLED Display (1366x768)
-- 90W Adapter
-- 4 GB DDR3 SDRAM 1333MHz (2 DIMMs)
-- Wave Systems Software
-- Information
-- 125V Power Cord
-- Information
-- Information
-- Alienware AVATAR 5
-- Software
-- Software
-- Software
-- Dell Wireless 1520 802.11n Half Mini-Card
-- Processor Label
-- Integrated Webcam
-- Genuine Windows 7 Home Premium 32-Bit Operating System DVD
-- Documentation
-- Processor: Intel Pentium U5400 (1.2GHz, 3M cache)
-- 1 GB  NVIDIA GeForce GT 335 M
-- Service Software
-- Information
-- No Internal WWAN Antenna Installed
-- Command Center
-- Image Restore Software
-- Information
-- Alienware M11x-R2: 1 Yr Ltd Warranty, In-Home Service after Remote Diagnosis (Included In Price)

Thanks!!