Macbook Pro Memory Question

Posted:
in Current Mac Hardware edited January 2014
Hi all,



I am planning to upgrade my MBP's memory. I currently have the 2GB of RAM that came with my notebook. I have a 15" C2D 2.33Ghz. Am I correct in thinking that the maximum amount of memory my notebook can use is ~3.1 Gigs?



I currently have 2 plans.



1) Keep one of my factory sticks in my MBP and buy a 2GB stick.



2) Buy a 4GB (2x2GB) kit and put that in.



If I go with option 2, what will happen to that extra gig in my computer? Also, I know that having two memory sticks of the same size (like 2x2GB) is faster than two difference size sticks (like 2GB + 1GB), can't remember what it's called though. Anyway, how much faster would the 4GB option be than the 3GB one?



Thanks in advance for responses.

Comments

  • Reply 1 of 2
    robmrobm Posts: 1,068member
    PITA post here, sorry 'bout that ... what apps are you running ?



    If you're just going to be "running around" with simple stuff its likely you'll see next to no benefit from where you are right now. But if you're running apps that can actually use gobs of ram then max the sucka ... can never have too much ram, that's what momma always said.
  • Reply 2 of 2
    Quote:
    Originally Posted by aiolos View Post


    If I go with option 2, what will happen to that extra gig in my computer? Also, I know that having two memory sticks of the same size (like 2x2GB) is faster than two difference size sticks (like 2GB + 1GB), can't remember what it's called though. Anyway, how much faster would the 4GB option be than the 3GB one?



    What happens is that the memory controller is only capable of addressing 32 bits of memory space, even though the processor is 64-bit. 32-bit memory space = 4GB. The reason you don't get that full 4GB is because every component in the computer has reserved some part of the address space, and that gets taken off the top, leaving 3-point-something for the operating system and apps. The RAM doesn't disappear, it just can't be used for anything else.



    Matched pairs of RAM run in Dual Channel mode, which doubles the memory bus bandwidth. That sounds impressive but the overall effect on performance is about 3-5%.
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