Memory heap spaces and garbage collection are frequently discussed yet are often the most frequently ignored benchmarks. With DL4J/ND4J, you can configure two types of memory limit: on-heap memory and off-heap memory. Whenever an INDArray is collected by the JVM garbage collector, the off-heap memory will be de-allocated, assuming that it is not being used anywhere else. In this recipe, we will set up heap spaces and garbage collection for benchmarking.