Early 2011 model, A1278 / 2.3 GHz i5 or 2.7 GHz i7 processor.

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Memory upgrade works partially

Hi everybody,

On my MacBook pro 13 early 2011, I upgraded RAM to two 8GB modules as it was adviced will work. However, my machine only recognizes 4GB out of each module hence 8GB total.

Any idea how to make it use whole 16GB available?

BTW, It works fine with new memeories

Update (12/19/2016)

Dear folks, Under 'About This Mac' it shows both slots are in use but each one 4 GB instead if 8 GB each.

Hardware Overview:

  • Model Name: MacBook Pro
  • Model Identifier: MacBookPro8,1
  • Processor Name: Intel Core i5
  • Processor Speed: 2.3 GHz
  • Number of Processors: 1
  • Total Number of Cores: 2
  • L2 Cache (per Core): 256 KB
  • L3 Cache: 3 MB
  • Memory: 8 GB
  • Boot ROM Version: MBP81.0047.B2D
  • SMC Version (system): 1.68f99
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Here's the specs for your system: MacBook Pro 13" 2.3 GHz i5 (Early 2011)


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2 Answers

Chosen Solution

Sounds like the modules you bought are only 4 GB units not 8 GB units.

I think you'll need to return them to get the correct ones or get your money back and order a new set from someone else.

If you go to 'About This Mac' > 'System Report' > Click on Memory in the left column and then resize the right column sliding the bar up so you can see the details of the two modules. Take a screen snapshot to show us (pasting it in your question) and the person you bought the units from.

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Dan, Thanks for your answer

in 'System Report' it says each module is 4GB but on the chips themselves (the paper sticker) it says each is 8GB. I'm confused


I guess they are mis-marked!

It's not possible for the modules to be 8 GB units and only be 4 GB seen unless the ID chip was mis-programed (what you are reading from the report).

You'll need to return them sorry ;-{


I checked the part no. it appears that the lable is not correct. I checked it on another laptop too


Thanks Dan, wondering why each slot only recognizes max 4gb


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Most Helpful Answer

It sounds like the issue is that it's not recognizing the RAM in one of the slots.

If you click the memory pane under "About This Mac" does it show both slots being occupied by 4 GB or 8 GB modules?

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You may want to check your systems firmware. Here's a good Apple T/N that goes over it: About EFI and SMC firmware updates for Intel-based Mac computers. Make sure yours is at or newer than what is listed. FYI: The version number is in hexadecimal!


Your firmware is newer than what the TN which is good!


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