Choosing processor for new Alienware's m11x

Hello,I'm thinking of buying this laptop and i don't know if the corei7 is worth the price. how better is it over the corei5 option?

Hello and welcome to the forums
What's your usage ?

For those tasks,an i3/i5 suffices IMO.

You can find some benchmarks here: http://www.notebookcheck.net/Mobil [...] 436.0.html

If you want to play Steam games on higher settings, you probably want something else, because the M11x has a not-so-good GPU.

It appears I underestimated the GTS 335m. L4D2 on maxed apparently does 44 fps.
I change my recommendation--you can probably make do with that.

i7 is of course better than i5, but because the GPU (while better than I had thought) is still not that great, most games are going to run into trouble with the GPU. For that reason, getting an i7 probably isn't worth it, because almost no games are going to need that good of a processor with a GTS 335m.
I don't think it's worth it, i5 is already great and i7 would make your computer pretty out of balance.

Thanks, do you really think the 335 GTS isn't powerfull? I think 30fps are ok, am i wrong?

GTS 335M is powerful enough to run games fine. You won't be able to max recent stuff, but medium settings should work for most games. The i7 is a CPU that could max recent games IF it had a GPU like a Mobility Radeon HD 5870. The GTS 335M is nowhere near that. You don't need the i7.

Actually thats quite wrong, the the i7 and i5 in question are of the UM version(i5-520UM, i7-640UM).
upgrading the CPU in such a system is pretty much unrealistic.
The i7's cache is 1mb larger and about 14% faster, the price is about 14% higher as well so you pretty much get the larger cache "for free".
I'd definitely go for the i7.