ICC stands for 'Integrated Circuit Card' The GPU is integrated on the motherboard
Advantage: Mobility Disadvantage: If the ICC chip (gpu) fails you need to replace whole motherboard.
i have a dell inspiron 7520, it has the radeon 7730m and it is fantastic it will run any game medium to high settings and it looks great, i definitely recommend the 7730m, the 7730m is an dedicated card so it is NOT integrated what so ever, it runs metro 2033 on medium to high settings with 50 to 60 fps
It does not mean onboard integrated graphics, it is indeed DEDICATED but the chip is soldered on the motherboard, (i.e. ICC card) not like desktops, separately fixed in a pci-e slot (i.e. removable graphics card)
The GPU failure will cause to REPLACE the whole motherboard, removable GPUs don't.
The NVIDIA GeForce GT 640M definitely performs better than the AMD Radeon HD 7730M.
Either GPU will soldered to the portable's motherboard and cannot be upgraded.