Ive been checking out notebooks with the ATI Radeon 4650 and most say it is 1GB, however when doing configs on Prostar and Sager, they list it with 512MB. I tried checking on the ATI website but they dont give specs on individual cards, just info on the 4600 series. Is it a case where the 4650 comes in both the 1GB and 512MB option? Any info would be great, thanks