Only a GTX555.
Plus it's Alienware which means overpriced to the max. For that price, I have a 3.0GHz Quad Core, 8 GB DDR3, 1TB HDD, and GTX 560 Ti.
I'd recommend building your own PC and ordering parts from NewEgg.
It's pretty easy. Just watch a video on youtube that goes through a tutorial as you build a PC. It becomes pretty straight forward!
go to cyberPC. they have nice and cheap PC/laptops for around 1.1k and under that run very smooth. also, dont go alienware if you have a 900 $ budget generally their PC's are over priced and arnt quite worth it past aesthetics. you can get more for your money by using cyberpc.
how do i not know anything??? check Cyber PC they have good PC/laptops for reletively cheap and as ive heard they run very well. Alienware are good but not for the money. for the same price of 1k alienware i can get a much better PC elsewhere. they are good, but most of the cash is used to pay for the case and lights, the internals are just over priced
Getting a shop built pc should be ok if you buy the right parts. If you are in the states you should be able to get a custom rig with an i5 2500K chip, z68 mobo, small ssd (120gb-plus), and medium hdd, 8gb ram, with a decent gpu (at least a HD6850, get 2 or a better one if possible), and a case with proper ventilation and room to upgrade for around $1000 (no monitor). You should get a 800W-plus psu so you can upgrade to 2 gpus in the future.
That dell looks neat, but I'd worry about overheating in such a small case.