Which RAM to choose from 2 options?

Question

RAM

There are 2 sets of ddr3

• 32gb 1333
  
• 16gb 1866
  

which is better to choose and why?

addition: to work with software and a large number of small files
, the mother has 4 slots in total, xeon 2670 stone

Answer 1

It would be nice to know: for what?
In the meantime, the answer is 32gb 1333, twice as much.

Answer 2

Depends on your motherboard and processor (number of slots, maximum capacity)