MacBook – Installation of RAM making MBP slow

macbook promemoryupgrade

Is there any reason why the installation of a RAM, larger than recommended, cause MBP to slow during startup and during normal working?

I am trying to understand the cases I didn't foresee when I went for higher than recommended RAM.


I have:

  • mid-2012 13 inch MBP;
  • running macOS Sierra;
  • recommended RAM for this machine is 8GB but I installed 2X8 (aka 16) GB RAM replacing my earlier 2X2 (aka 4) GB RAM.

Best Answer

There can be several reasons.

Firsts, new RAM can be slower than your original RAM. Compare original RAM specification and the one you installed. For Macs manufacturers usually have specially tested and tuned RAM modules. Anything cheap will actually decrease performance.

Secondly, Mac allocates as much swap as you have RAM. Earlier your Mac allocated 4GB at start, now it has to allocate 16GB. If you do not have SSD, this will be much slower because the swap file has to be written to disk at start.