Right now i am using a dell inspiron 620 with 2x2 gb 1333mhz ram and an i 3 2100 cpu. I want to upgrade to 8(2x4) gb ram, but i dont know what i should do. Dell and intel says to use 1333 mhz ram only, but crucial recommends me to use 1600mhz ram(PC3-12800) . Can anyone tell me what to do?