my recamend is Buy "TRANSCEND" ram .reason other manufacturers give only 1year warenty but transcend give "lifetime warenty" so no need to warry about problems. Then cost "no more dealer and distributer " because anyone can "buy directly in TRANSCEND.COM" so cost lower then other.
My recamend is fill all slots dont see capacity. see mhz in board and ram.Reason mhz is the key to achive speed. if board support 1600mhz u insert 1333mhz its waste because not get full speed of ram slot. if board support 1333mhz u insert 1600mhz its also waste of money (1333mhz ram is cheaper than 1600mhz)also u not utilise full speed of ram. (4x1600mhz=6400mhz =6.4ghz) vs (2x1600=3200mhz=3.2ghz). think.