what graphics card is better?

I am looking at buying a gaming laptop to replace my gaming desktop.

This is what I have in mind:
General Information
Model Number ROG G53Sw-XR1
Lifestyle Gaming
Color - Lid Black
Color - Base Black
Color - Keyboard Black
Platform Notebook PC
Motherboard
North Bridge Chipset Intel HM65
Operating System
Operating System Windows 7 Home Premium 64-bit
Processor
CPU Brand Intel
# of Cores 4
CPU Type Core i7
CPU Speed 2630QM (2GHz)
Turbo Boost Speed Up to 2.9GHz
Smart Cache 6MB
CPU Main Features Hyper-Threading Technology
Virtualization Technology
Turbo Boost Technology
Intel 64
Enhanced Intel SpeedStep Technology
Idle States
Thermal Monitoring Technologies
Intel Fast Memory Access
Intel Flex Memory Access
Trusted Execution Technology
Memory
Total Memory 6GB
Memory Speed DDR3-1333
Form Factor 204-pin SO-DIMM
Memory Configuration 1 x 4GB; 1 x 2GB
Memory Slots (Total) 2
Memory Slots (Available) 0
Maximum Memory Supported 8GB
Hard Drive
HD Capacity 640GB
HD Interface SATA
HD RPM 5,400 RPM
HD Configuration 1 x 640GB
Multimedia Drives
Optical Drive SuperMulti DVD±RW
Optical Drive Interface SATA
Display
Screen Size 15.6"
Display Type Full HD LED-backlit LCD
Resolution 1920x1080
Widescreen Yes
Webcam Yes
Webcam Resolution 2.0 Megapixel
Video
GPU Type NVIDIA GeForce GTX 460M
Video Memory 1536MB
Display Interface 1 x VGA
1 x HDMI
Audio
Audio System High Definition Audio
Speakers Yes
Communications
LAN Gigabit LAN
LAN Data Transfer Rate 10/100/1000Mbps
WLAN Wireless LAN 802.11b/g/n
Wireless Technology 802.11b
802.11g
802.11n
WLAN Data Transfer Rate Up to 150Mbps
Bluetooth Bluetooth 2.1
Card Reader
Card Reader 8-in-1 Digital Media Reader
Media Supported Secure Digital
MMC
Memory Stick
Memory Stick PRO
xD
Mini SD
Memory Stick Duo
Memory Stick PRO Duo
Ports and Connectors
VGA 15-pin 1
HDMI 1
USB 2.0 3
USB 3.0 1
LAN RJ-45 1
Audio 2
Security
HD Password Protection Yes
Keyboard & Mouse
Keyboard Ergonomic Illuminated Keyboard
Mouse Type Touchpad
Power
Power Supply AC Adapter
Battery 6-Cell Lithium-Ion
Physical Specifications
Width 15.6"
Depth 11.9"
Height 0.8" - 2"
Weight 7.9 lbs.
Box Size 18.5" x 6.8" x 15.3"
Shipping Weight 12 lbs.
What's in the Box
What's in the Box ROG G53Sw-XR1 Laptop Computer, Driver CD, Manual Pack, Battery, AC Adapter
Preloaded Software Adobe Reader 9
Power2Go
Trend Micro Internet Security 2010 60-Day Trial
Manufacturer Warranty
Parts 1 year
Labor 1 year
Battery 1 year

My question is: will the geforce gtx 460m outdo my desktop's Ati Radeon HD 5770 1GB GDDR5?
I know there is a difference between Ati and Nvidia and now I'm also trying to compare it to an Ati Desktop card. Hope to figure this out, as I need to sell my desktop in order to get this laptop and didn't want to sell it if it turned out to be a major downgrade. Oh, I know the laptop outbeats my desktop in the other areas, some not by too much, but the graphics is where I am questioning.

Thanks for your help.
I am a student, so i need ultimate portability, please only answer the question I asked. I know what I want, was only wanting to know the differences between systems. That and no, it's not cheaper to have a laptop built. I've compared to those that will build them, this is the best deal at $1300. Other's want around at least $1500-$2500. thanks
i didn't want to put anyone off, so please don't be offended by my first Additional details remark.

I Recommend not even buying the laptop, and just either, Building your own Or Finding a shop or finding Someone that can just  build you a new gaming desktop, Because it will be Much cheaper
Dont get ripped off with high street prices, and also buying a gaming Laptop is a bad move because you cant upgrade the parts inside of a laptop, Because quite quickly computer parts become obselete and will not be able to play the latest games, I Bought a Dell Studio 1555 for £700 Ati Graphics card 512mb Dedicated Video Memory Total Video Memory 2.2Gb
4Gb Ram 2.0Ghz Pentium Dual core t4200 Processor
I recently started to think of upgrading my Processor and Graphics card until i found out that i couldnt..
So instead i started researching the prices of building my own desktop and sure enough the prices were drastically lower, I Could build myself a super gaming machine for around £400
and its not very complicated, Bear in mind im only 13 years old
But to answer your question i would stick with your Desktops graphics card because theres no need to upgrade to that laptop graphics card anyway yet, And real graphics cards like your Desktops one, always outdo the laptop ones, But correct me if im wrong
Hope i helped you out making your decision

You'll need a 485 to do that!