I7 620m

no ive got a m15x from aw with a i7 720

Why do you want a 620m then? The 720 is nearly as fast single threaded, and faster on multithreaded stuff.

The core i7 720m is a quad core cpu

So in multi threaded stuff (like video editing is one option), the core i7 720 will win due to it's 8 threads vs the core i7 620 4 threads.

As for The speed, yes at quad core state it's only a 1.6 Ghz cpu but in turbo boost,

it can be a 2.4 GHz dual core cpu or a 2.8 GHz Single core cpu. (depending on app.)

Also the 720m can run max ddr3 speeds of 1333MHz vs the 620m speed of ddr3 1066MHz


For the core i7 620m is a dual core cpu at stock speed of 2.6 GHz

For turbo boosts (im not sure if this is single core or both cores at this speed. I think it's single core though.) 3.33GHz

Well guys to help answer the first question: some international eBay listings have emerged (china & uk) for QS (qualification sample) i7-620m's for around $300. These work just like the retail version but consider them the equivalent to a final Beta prior to release.

As for "upgrading" to a dual core, the speed argument has already been discussed in good detail. The 620m will do better in single & dual core activities (ex: games) while the quad core 720 will outperform in multi-threaded apps like video / photo editing & encoding.

One big thing not discussed was the thermal heat factor! The quad core mobile i7's (720) are notorious for running extra hot even in the best designed laptops (search Macbook Pro i7 for a ton of complaints about super hot heat). The dual core i7's (620 & 640m) run a lot cooler.

I'd go with a i7-640m if you want the best dual core mobile processor on the market! Just make sure you use some high quality thermal compound (arctic silver or TC diamond) when you stick the CPU fan back on. Laptop upgrades aren't for the timid so youtube some clips because I'm sure a lot of Alienware laptops are easily upgradable.

Good luck and don't get suckered by the quad-core hype unless you are in video / photo editing & production.