Q. How many instances should run on a CPU with N cores for better performance?
From the docs, I found out that one instance has three threads (network, transaction, and WAL). I suppose that each thread should run on its own core. Therefore it’s better if N/3 instances run on an N-core CPU. Is this right? (2017)
A. Your number of instances should be ⅔ the number of CPU cores: the other two threads do not take as much CPU as the transaction thread.