3 Replies Latest reply: May 18, 2012 2:02 PM by LambdaEnt
LambdaEnt Level 1 Level 1

I undertstand most of the issues of 3GB vs 4GB installed in this computer, as explained very well here:

http://www.everymac.com/systems/apple/macbook_pro/faq/macbook-pro-core-2-duo-3-g b-memory-limitation-details.html


With two 2GB chips, the computer might recognize just 3GB.


But is their any dual-channel advantage by installing a matched pair (two 2GB), instead of one 2Gb and one 1GB?

MacBook Pro, 2.16GHz Intel Core 2 Duo 15.4"
  • ds store Level 7 Level 7

    LambdaEnt wrote:


    With two 2GB chips, the computer might recognize just 3GB.


    The computer recognizes 3.5GB is what I understand, or else why bother and just use a 2GB + 1GB right?


    I think the article is trying to say is there is a problem with memory overlap when one uses 2 - 2GB for 3.5GB and that they would be better off using 2GB + 1GB for 3GB to avoid the overlap.


    However one would lost the .5GB and have to swap slightly more often to storage.


    The older 32 bit Mac's, if you have a 7,200 RM drive (or splurge for a small SSD) then the swap is faster, so 3GB + a fast storage would likely be better than having memory overlap with 3.5GB.


    I replaced my older 15" with a 7,200 RPM and 4GB of RAM and the performance improved greatly, I really didn't have any problems until I install OS X Lion on it and that killed it deader than a doornail.

  • LambdaEnt Level 1 Level 1

    That's all nice, but had nothing to do with my question.

  • Csound1 Level 8 Level 8

    There are advantages to matching pairs, buy 2x2G.

  • LambdaEnt Level 1 Level 1

    I'm sorry, I just re-read your reply. The question was regarding dual-channel. But overall, it was about performance.


    When you upgraded to Lion, did you run Lion Cache Cleaner?


    I have found ANY OSX upgrade always suffers serious performance decreases. LCC solves the issues.