Fundamentals guides

Build the memory model before changing the machine

Begin with the difference between physical RAM, virtual address space, and swap backing. Then connect those terms to the workload you actually run. A saved file's size, a process's virtual size, and the memory it actively needs are not interchangeable measurements.

The fundamentals articles answer two distinct questions. The RAM-versus-swap guide explains what happens and how to interpret a memory readout. The sizing guide turns that understanding into a plan covering expected peaks, acceptable delay, storage headroom, and recovery requirements. Read them in that order when the terminology is unfamiliar.

For a short introduction, start at Mem Swap. For a planning worksheet, use RAM Memory Swap. These pages help you decide whether the next step is more observation, a capacity change, or an application-level experiment.

Keep a small record of the task, input, background work, and symptom. A good baseline makes the later platform-specific guides easier to use. The objective is not to discover a number that suits every machine; it is to understand the particular work your machine must complete.