IMac 27 3.2 GHz core i5 [late 2013] memory upgrade


I'm thinking to upgrade memory on my iMac 27 3.2 GHz core i5 [late 2013]. It has currently built-in 8GB [4GB x 2] RAM. My questions are:

1] Can I upgrade RAM by simply adding 16GB [8GB x 2] in two empty ram slots? Or is it necessary to have 4GB x 2? Does it have to be 4GB… won't work with 8GB module? Is it that all modules have be with same capacity? Can I make it [4GB x 2 – built-in] + 8GB x 2 – to be added] 24 GB?

2] Does memory module designed for i7 work in i5?

Best Answer

You can upgrade your iMac with 2 x 2 GB, 2x 4 GB or 2 x 8 GB PC3-12800 DDR3 1600 MHz modules. If you buy a pair of identical modules and install them in one bank you will benefit from memory interleaving. The first bank are slot 1 and 3 which already are occupied by the Apple OEM modules. The second bank are slot 2 and 4.

Memory modules aren't designed for the marketing name of a processor but for a system architecture. The six generations of ix-processors (i3, i5, i7) support at least seven different types of modules (but every generation only a subset of the listed):

  • DDR3-800
  • DDR3-1066
  • DDR3-1333
  • DDR3-1600
  • DDR3-1866
  • DDR4-1866
  • DDR4-2133

Some ix-processors even support ECC-modules.

In Mac models the memory modules are usually interchangeable between the i5 and the i7 variety of a particular machine (e.g. iMac14,2 i5 and iMac14,2 i7).