I have a late 2008 Alu MB and it's currently using 2 GB RAM. I'm thinking of upgrading to 6 GB through this http://eshop.macsales.com/item/Other World Computing/8566DDR3S6GP/ How much faster would my MB be? I'm using it mostly for photoediting via Lightroom and PhotoShop and sometimes video editing. I also watch 1080p movies. Would there be a noticeable difference in any of that? Thanks.