Is it better to upgrade this with a single 4GB DDR2 RAM fitting in one slot, or a kit of 2GB DDR2 RAMs fitting in both slots? I'm pretty sure it can handle 2GB in each slot but I'm not really sure it can handle the full 4GB all in one place. Yet it seems to be a more battery conscious decision to occupy only one ram slot (?).
Secondly, I wanted to ask your opinion on RAM speeds, would it be better to get the higher RAM speed (640Mhz) even though its full speed wouldn't be supported or would it be wiser to just go with the 533 Mhz RAM?
Thank you so much, I've done a lot of Googling on this but I'm still confused.