At ~7000 on Geekbench, I don't know how a Macbook can make use of 16GB at a time. My early-2013 Macbook Pro does 12000 on Geekbench and I think it seldom needs more than 8GB. It only needs 16 (or even 32GB) on bad coded applications, like ImageMagick when doing conversion of image-based PDFs with hundreds of pages. This happens only because it allocates memory for all pages instead of processing only one page at a time per core.