Building your Neo4j instance(s) with the right hardware is essential to running a successful cluster. Neo4j runs best when there is plenty of RAM at its disposal.
One aspect to consider is that Neo4j runs on a Java virtual machine (JVM). This means that you need to have at least enough random-access memory (RAM) to hold the JVM heap, plus extra for other operating system processes. While Neo4j can be made to run on as little as 2 GB of RAM, a memory size of 32 GB of RAM (or more) is recommended for production workloads. This will allow you to configure your instances to map as much data into memory as possible, leading to optimal performance.