Will there be issues if I install RAM modules with different sizes in a Mac mini? I have a Mac mini late 2012 with 4 GB (2 x 2 GB) RAM. I bought another 8 GB RAM module and installed it in the Mac. Should I leave the 8 GB module alone or should I install one of the two 2 GB modules in the vacant RAM slot?

Will there be any issue if there are different RAM modules in the slots (8 GB + 2 GB)?
If the two different sized RAM modules have the same specifications (e.g. latency), you shouldn't have any issues.

The advantages - more memory - outweigh the disadvantages of different sized modules - no interleaving memory.