Need some advice on laptop GPU

[EmpathyFX]

Hi, I'm going to be purchasing a laptop real soon but I'm kind of stuck at one part. The graphics cards.

Here's an image of the options I have available to me.

Now originally I was going with the 3rd option:
Dual AMD Radeon HD 6990M w/2GB GDDR5 (total of 4GB) CrossFireX Technology + 2nd AC Adapter with Power Converter Box [add $575.00]

I asked a few friends of mine but no one seems to be quite sure on which route to go.

Pro-Star:website
Model: X7201-A1

I'm purchasing the laptop from pro-star and it's going to cost me $5,284 with these options:

Spoiler

I'm really not good with hardware and I can't really get into much detail about it. Any advice and opinions please share. I'm trying to get this purchased by this weekend for school. I'm really wondering what the big price difference between the dual 580's & the dual 6990's is all about. I'm worried about air, how loud it will be and any heat problems. Thanks in advance.

 

[The Halo Don]

One GTX 580 or one 6990 would max out any game without any problems!

Why get two?

I see no point, but I heard that crossfired 6990's run HOT, but I dont know too much about the GTX 580's.

And 5,000 for a gaming laptop?

You could build 5 AMAZING DESKTOPS for 5,000, I say buy a $500 laptop for school and spend like 1,700 on a gaming desktop.

 

[9_breaker]

the Asus g74 has almost the same specks and its 2700 .it's alot but its about half price. it even looks way better than all the laptops I've ever seen. there's only one problem, its huuuuuge.

 

[Supernova1138]

A single 6990m is about equal to a desktop 6870, it will be able to max out most titles at 1080p. Dual 6990ms is probably overkill unless you really want to max out Crysis 2 or Metro 2033 on your laptop. I imagine the dual GPU laptop setup would also present heat problems, and battery life would be atrocious. Unless you absolutely want to have the very best in mobile gaming and are willing to spend that kind of money, you might be better off going for the cheaper version with the single GPU.

 

[Archean]

+1 super
Only fix for the heat issue would be to have a reasonable quality cooling pad, which would hamper your mobility anyway.

Also I wouldn't bother with the older generation 990 CPU, which runs hotter, and a higher end SNB will pretty much do all what you want to do without any hitch.

Lastly, buying an extremely expensive notebook isn't something I'd recommend to anyone, because the price/performance ratio just doesn't add up IMO.