» Fri Dec 09, 2011 1:19 pm
My two cents, Alienware makes a great machine, but they are a bit overpriced. Depending on your situation, you might be better off looking elsewhere. I won't labor over the points that others already have, that laptops obviously dollar for dollar will severely underperform desktops, that's a given, but I'm sure you have your reasons for wanting a gaming laptop.
I highly recommend the ASUS RoG series. My laptop only cost 800 dollars and is on par gaming performance wise with a 1600 dollar laptop. http://www.newegg.com/Product/Product.aspx?Item=N82E16834230021
I am able to play Skyrim on Ultra with shadows set to high along with shadowed land, shadowed trees, and increased tree draw distance, and I get 60 FPS in dungeons/caves, 35-45 FPS outside and in towns, with occasional in town drops into the 20's (the well-known 'bad' spots in Markath for example). The laptop has some issues which you may need to fix (when I first purchased it, the first game I fired up immediately GSoD'd (grey screen of death), but I knew this was a possibility. A simple VBios update and I've never had a single problem with stability since. The GPU comes stock at 700/1000MHz core/memory clocks and I was easily able to OC it to 800/1000MHz core/memory and am rock stable. The laptop also has a subwoofer, which while obviously laptop speakers will always underperform good headphones, the 2.1 speakers on this laptop are better than any other laptop speakers I've ever used.
IMHO, this 800 dollar laptop will outperform all but the most extreme gaming laptops, only downside is 1600x900 monitor instead of 1080p, but in some regards that could be viewed as a positive, since you always want to play games on LCD at their native resolution because LCD panels have a fixed raster. So if you got a 1080p laptop, and then ended up being forced to run games at a lower res anyway, you'd actually be getting a worse image quality. I can't sing high enough praises about this laptop at that price point. If you compare the performance of the mobility 5870 with other mobile GPU's, here: http://www.notebookcheck.net/Comparison-of-Laptop-Graphics-Cards.130.0.html you'll see that it's almost on par with the GTX 560M, which is pretty incredible.
TL;DR: You can find laptops with slightly better performance than the one I linked, but not at that price point. 800 dollars gets you a laptop as fast (gaming-wise) as most 1500+ builds. For desktop performance, not having a sandybridge might slow you down just a tad, but if you look at benchmarks, clock for clock, sandybridges don't really outperform equally clocked non-sandy counterparts. For non-gaming, clock for clock, the sandybridges are almost twice as fast as an equally clocked non-sandy, but honestly the i7 740m is a plenty powerful processor for desktop use. I regularly transcode video while watching HD video and lots of other taxing things without any issues.
ninja edit: If you do go with this model, I recommend formatting it and reinstalling Windows to get rid of the bloatware. I got significantly better performance after doing a clean install compared to just trying to stop all the bloat-services and uninstall all the bloatware.