Alienware M15X Customization question

[sadseada123]

.OK.Now i own a alienware aurora desktop with the following specs
Intel core i7 870
6GB 1600MHZ DDR3 RAM
500GB HDD
650 WATT PSU
MSI Nvidia geforce gtx 260 1792MB Single card lightning edition superclocked
now i want to buy an alienware m15x for some mobile gaming.the gtx 260m is costing 100 dollars more than the GDDR5 ATI Mobility radeon 5850.Now I am a nvidia fan but is the gtx 260m that much better than the 5850 by 100 dollars coz from what i heard the 5850 is a awesome card.which card could give me the bst closest performance to my current desktop?

 

[Maziar]

The GTX 260M is actually slower than a 5850M, i haven't no idea why it costs $100 more,so go with 5850M,its cheaper and better.
A 5850M performs pretty much like a 5750 desktop( a little slower),so its slower than your desktop card.

 

[sadseada123]

and to what does the mobility 5870 compare?

 

[Maziar]

5870M performs between a desktop 5750 and 5770,so its still slower than a GTX 260 desktop.