A:Answer Here's what I found:
Dell Inspiron 5593 motherboard has two memory slots and according to Crucial website it can support up to 64GB RAM (2x32GB DDR4-2666 SODIMM modules).
On the other hand,
The official Dell Inspiron 5593 Setup and Specifications guide says maximum memory is 16 GB DDR4 (2 x 8 GB).
Crucial has a statement on their website "Compatible upgrades guaranteed". I would buy RAM directly from them and if doesn't work return it back.
I'm sure this model should take more than 16GB.
Both memory slots located under the bottom cover. I'll attach some pictures. If you need detailed Dell Inspiron 5593 disassembly instructions, just google my nickname. ;)
http://www.insidemylaptop.com/taking-apart-dell-inspiron-15-5593-model-p90f/
Good luck!