Ok, first of all i would like to say, I Want to buy this computer and this computer only. Keep that in mind please.

So I play the game runescape and i was wondering if the M15x stock, with maybe a 4gb upgrade and larger hard drive, would be able to play it on max settings with no lag. I would be using the stock i3 processor.

If not, what upgrades should i get?

The i7 processor?

Thank you for your time.

Answer:
The same thing I tell everyone, ALIENWARE is garbage. Alienware laptops are very prone to cracking and blue screening and they’ve horrible lifespans. Reasoning: high end GPUs and quad core CPUs cause tremendous amounts of heat, especially while being pushed by gaming (sadly, that's what Alienwares are supposed to be made for). Alienware laptops have a huge, thick plastic chassis (casing), plastic warps upon temperature changes (cracking). (∆L = L α ∆T, β = 3α, ∆V = V β ∆T) Also the extreme heat caused by the GPU and CPU tends to dry out the Thermal Paste which is designed to be a heat sink for the CPU and GPU. When your Thermal Paste dries out it causes overheating to occur which causes blue screening. Because of these issues, further damage may happen internally to your laptop, which is why the lifespan of those machines tend to run short. If you want a superb gaming machine purchase a desktop, it will be cheaper, superior, and made to handle the heat. As for a laptop, most newer dedicated GPUs can handle demanding games (CODMW2, Crysis, WoW). As for runescape, runescape is a browser based game, which has very little to do with your machine. The Alienware you are speaking about will run about $1800+ (if you get the i7, 620M is a dual core version of the i7 which is a rip, you might as well stick with an i5 for the price), you would be much better off getting this machine…

Toshiba Qosmio X505-Q860 ($1099.99)
-Intel® Core™ i5-430M Processor 2.26 GHz (2.53 GHz with Turbo Boost Technology), 3MB L3 Cache, 1066MHz DDR3
-Genuine Windows® 7 Home Premium
-4GB DDR3 memory
-500GB hard drive (7200 rpm)
-1GB GDDR5 NVIDIA® GeForce® 360M
-DVD SuperMulti with Labelflash®
-802.11n wireless
-Integrated webcam
-HDMI output
-Harman/Kardon® stereo speakers
-Fusion® Finish in Omega Black

This machine will have the same if not superior performance than the Alienware without the complications.
To find go to:
toshibadirect.com >> Laptops >> Qosmio >> Ultimate Gaming, Qosmio X505 >> See Pre-built models >> Qosmio X505-Q860

If you have any questions feel free to email me at thomasdemarie@rocketmail.com, I am here to help.

Answer:
you should upgrade the videocard. it would greatly improve your gaming experience. i7 is overkill. i3 or i5 is enough when paired with a high end videocard
Answer:
It should, yes, but I would get an i7 anyway just to “future-proof” it for another year so it won't go out of date so fast.
Answer:
wait for the dual i7 ;+)