Hi, I download COD 4 and it is really slow and jittery on my 13" standard MPB 2010 model. Is there any way I can add a graphics card so that I can get superior gaming quality? Also has anyone got advice on the best graphics card in terms of performance? And some advice on getting it up and running? I assume it will be external, as I dont think you can mod the internal graphics card can you? And is this process known as "flashing?" Thanks a lot.