I am considering btw these two: Acer Aspire V3-772G -16 GB DDR3,hd-1TB,Intel Core i7-4702MMQ,Nvidia Geoforce GT750M with 4gb DDR3. Lenovo y510p -16 GB DDR3,HD-1TB,Intel Core i7-4700MMQ,Nvidia Geoforce GT750M with 2gb DDR5. I wonder what's the difference between ddr5 and dddr3 when it comes to graphics cards.