Graphics chips usually reside in one of three places:
- On the motherboard.
- In the CPU / APU
- On a dedicated graphics card.
On most older laptops you will find the graphics build onto the motherboard. Replacing those usually comes down to replacing the entire motherboard. Essentially you get a new laptop in the same case. Possible with some laptop models. Usually expensive.
Consider that a no for practical purposes.
Many modern CPUs add a graphics core to their CPU. This is the case with your laptop. It has an Intel I5 CPU, with a graphics 3000 core. You can not replace this without replacing the entire CPU.
In your case that might be possible. Asus sells your laptop with three different CPUs:
A i3 2310M, i5 2520M and a i5 2410M
If you Intels website compare these three CPU's then you will notice that they have three differently clocked graphics cores. You could replace the laptop with the fastest one sold by Asus, or you could try to use another CPU. The last would need to be supported by the BIOS; it should not use more power; it should not generate more heat.
A few laptops come with dedicated graphics cards connected via standadised miniPCI or miniPCIe slots. You can change these if:
- You have such a (gaming) laptop.
- And you happen to have the right card which is supported by that laptop.
- And if the laptop can power it.
The last is non trivial. Some of the gaming laptops need three(!) power bricks. (Max power per standarised laptop PSU is limited and mobile gaming cards can draw up to 100 Watt per card). Some laptops even support crossfire or SLI.
The second bullet point is more subtle: miniPCI and miniPCIe have been standarided. But many laptop do not support all devices. It seems to come down to 'do I have my own brand card 1? No? then check if I have my own brand card 2 No? FAIL TO START. Even if they technically should work.
People without regard for their hardware have worked around this by booting their laptop, and inserting a miniPCIe card after it was past POST. That falls under the heading of 'do not try this at home' and 'quite impractical to do'.
Then there are a few rare laptops with MXM. Quoting wikipedia on that:
A Mobile PCI Express Module (MXM) is an interconnect standard for GPUs
(MXM Graphics Modules) in laptops using PCI Express created by MXM-SIG.
The goal was to create a non-proprietary, industry standard socket, so
one could easily upgrade the graphics processor in a laptop,
It is used in some Clevo and ALien ware gaming laptops.
That completes the answers to the three points I started with, namely where graphics parts normally reside. However since a few years there is a new bus on the market: thunderbolt
I see no technical reason why you could not connect any graphics card to that. It should be initialised early enough to be used by the OS.
In praxis it might be a bit harder to use: For once the BIOS needs to work properly. With laptops that is not a given.
However there are external cases on the market using powerful full sized desktop GPUs connected via thunderbolt. example.
It will be interesting to get this to work, but it is not a portable solution.
(I noticed you have a laptop which design point is 'superior portability'. Still, for completeness sake...)
That leaves your second question: I do not have any experience with windows 8 yet. But I see no reason why could you not do this if you have a laptop with MXM or Thunderbolt. (your laptop has neither of those two).