Difference between graphic cards on a gaming laptop. Which one is better?

They are nearly identical. You will be unable to distinguish between them. GTX460M= 1268 on Passmark, and Mobility 5870= 1263. The real question is why are you going for such an expensive card in a laptop? If you get a Desktop with a REAL GTX 460, it will have a Passmark score of 2327, and will cost less.

They seem quite similar.
This page compares the Nvidia chip with the Radeon 5000 series.

Between the two, I would go with the Nvidia for its greater GRAM.

I have had a lot of technical problems with my current ATI card, so on personal experience alone, I would go with Nvidia.
Also I have to state here that the graphic chips in laptops are, despite what it says in the title, not the same as their desktop namesakes.
They usually have lower gpu speed, less shader units and sometimes it is even an older chipset. You do not get what it says on the box.
So my advice is to get a proper Desktop Pc.

I am in agreement with these three. I like nVidia better, but question the wisdom of getting such a rig when you could get a far better gaming desktop for less. And by “better”, I mean something twice as fast that won’t overheat or suck down batteries so fast that they’ll need replacing in a year due to the heat generated wear on the Lithium-ion cells.

@ragingloli Actually, they usually are what they say on the box. However, many people don’t truly realize what that M on the end of the (nVidia) model number means, or the implications of the word “Mobility” on the Radeon chips. I think a 50% reduction in performance is a big enough deal to notice, but many people don’t.

Thank you guys for the answers. I realize that a desktop is way better than a laptop, but in my case I do want a laptop because I’m starting a job pretty soon that requires me to travel very often. And I finally found a website that explains that the JW is an update from the JH, and that the JW temperatures are significantly lower and that Asus fixed several problems or complaints from customers like the track bar and some other things. Cheers!

Considering that the last Radeon I had put out enough heat to double as a coffeemaker whereas my fanless GT240 is faster and far cooler, I am not surprised :/

And if the GPU is the same speed and all, 1.5GB beats 1GB. I would still be wary about actually having it on my lap when doing anything that really benefited from a decent GPU though.