MacBook Pro 15" 2011 slow with 2x 4GB RAM - but ok 1x 4GB

Hi everyone


I've upgraded my MacBook to 2 the same sticks of 4GB Samsung PC3 10600S (1333MHz) RAM and when 2 of them in - MacBook is slow in Youtube - even pointer - when with just one 4GB stick - everything works fine 😟


When I insert other one to check if its faulty - works great :/ same with one stick in first or second slot


Whats wrong? 😟

MacBook Pro, OS X Yosemite (10.10.4)

Posted on Jun 24, 2016 1:08 PM

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4 replies

Jun 24, 2016 1:17 PM in response to the_bart123

the_bart123 wrote:

2 the same sticks of 4GB Samsung PC3 10600S (1333MHz) RAM


2 of them in - MacBook is slow in Youtube


when with just one 4GB stick - everything works fine 😟


😟


Most likely a bad stick of RAM. If you swap banks with the operating RAM and it stops working then it is a bad bank.


The fix for a bad bank is a CPU replacement.


The fix for a bad stick is replace it with a good one. Most reputability dealer have a lifetime guarantee on RAM. Contact them once you sort it out.


Verify you have the correct spec on your new RAM using Crucial http://www.crucial.com/usa/en/systemscanner


If they are not working together then I would replace both sticks for a "better" matched pair—not your fault.

Jun 24, 2016 1:33 PM in response to the_bart123

Even Apple did diagnostic and said it passed tests - but it is slow - and offered me very expensive Motherboard replacement


P.S. It passed video test recall

Now the details come rolling in.


Put the factory RAM back in, same problem would point to a defective CPU.


However Apple will test with factory spec RAM, not your user upgraded RAM.


I still suspect you have a mis-matched pair. Buying bad RAM is not that uncommon, unless the above test is the same result.


You can ask for the Apple Depot Repair Service—less expensive way to go, turn around time is 1 week.

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MacBook Pro 15" 2011 slow with 2x 4GB RAM - but ok 1x 4GB

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