Video card question

So, I start to glaze over on the technical stuff, but I'm trying here.

I need a new computer, for school. I really want a laptop rather than a desktop. A desktop means sitting in the other room, and eventually avoiding school work, not good.

So in my bare minimum computer requirements I need a video card listed as:
Navidia GEForce 6600 or better
ATI Radion 8500, 9250 or better.

I assume those are video cards for desktops.

The best (in my preferred price range) for the laptop are video cards:
Navidia Geforce GT525M and the some what slightly better GT550M (with Optimus)

so what I can figure out is are the laptop video cards actually better than the 6600, I can find where they compare to each other but not how they compare to desktop cards, to see if they will work.

Other than the general: desktops are better laptops for gaming.

I get that laptops are not the greatest, but are they at least good enough?

Can anyone shed any light on to how these video cards compare to each other? my searching of the web is just leading to a more confusion.

Both the GT6600 and the ATI 9250 are old technology. What application are you most concerned with being able to run?

Yeah them being old, is not helping matters either and It looks like ATI is AMD now?

but yeah, it's mostly Second Life that is going to using the graphics card, everything else I have to use has different or lesser requirements.

It's kind of difficult to say without actually trying them, as to which is going to give you the best bang for your buck. There are many variables, connection speed, GPU speed, RAM, and drive speed are a few. I doubt if you'll get full resolution with shadows on with either of the GPU's you are looking at.

I know you have a budget, but have you looked at the Alienware series laptops from Dell? This one Alienware M14x would probably do the job for you.

hmmmm so that alienware is sporting the GT555 with optimus.
That does kinda help, and its not that much more than the other dell models I'm looking at, though I would prefer it a little less, but who wouldn't

I also don't know how much time I actually need to use Second life, just that I need to use it. if its just a few hours here or there, being a little slow rendering stuff isn't going to bother me, too much, as opposed to if I were a hard core gamer and already invested in the game.