I'm looking to upgrade my MBP 15" from 4Gb to 8. I currently have 1066 MHz but looks like most stores (at least those near me) only sell 1333 MHz. Is it okay to change from 1066 to 1333?
More aboutreplace 1066mhz memory 1333
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Yes, you can do that as long as you don't change the DDR 2 to DDR 3 - the worst case scenario would be that the 1333 RAM would clock down to 1066. The RAM specs are determined by what motherboard you have.
Clarification: If it is DDR 2 stay with DDR 2 - if it is DDR 3 stay with DDR3 - whatever the motherboard supports. Do not switch between the 2.