I have a Mid 2012 13-inch MacBook Pro. To speed it up, I bought two Kingston PC3L-12800 1600 MHz memory modules which have 4 GB each. However, my computer keeps showing the famous "beach ball" if try to do to many things at the same time (keeping multiple tabs open, closing applications one after another etc).

Do you think there is a compatibility issue? If so, is there a way that I can solve it?

  • Did you already install them? Does the computer boot up? If you go to “about this mac…” home much ram does it say you have? Apr 18, 2020 at 9:18
  • Yes, it recognizes the modules properly. However, when I do many things on the computer, the system just locks down. The screen freezes and I have "beach ball" instead of the regular mouse cursor. Apr 18, 2020 at 19:33

1 Answer 1


Yes, there's a problem:

PC3L ≠ PC3.

PC3L is PC3 Low Voltage memory that operates at 1.35V and PC3 operates at 1.5V. The 2012 MacBook Pro calls for PC3-12800. See Everymac.com. For best results you want to use the exact memory, or higher quality memory that operates at both voltage levels.

Also, that Mac is capable of 16GB of RAM, and the price point is low enough that you could max it out for only a marginal amount more. Nobody ever said "Gee I have too much memory!" It's better to have and not need than need and not have!

  • So are my RAMs completely useless or is there a method that I can make them work? Apr 17, 2020 at 21:32
  • You can't force memory to use higher voltage - it either is capable of it or it isn't
    – Allan
    Apr 17, 2020 at 21:36
  • Alright, thank you for the quick reply! @Allan Apr 17, 2020 at 21:37
  • @FrenkFrenk One might note that the RAM is completely useless to you on your MacBook Pro. But because someone manufactured them, they'll fit...something. Apr 18, 2020 at 0:39

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