Resources & limits
Two independent knobs control memory, plus optional hard CPU/RAM ceilings — with live usage graphs.
Heap vs. hard caps
| Setting | What it is |
|---|---|
Heap (-Xmx) | The JVM's own heap size. Cooperative — the application stays within it, but nothing forces it. |
| Memory cap | A hard process memory ceiling enforced by the OS. The server can't exceed it. |
| CPU cap | A hard CPU ceiling, in cores' worth of time (e.g. 2 cores). |
Hard caps are enforced by cgroups v2 on Linux and Job Objects on Windows. Leave a cap blank (zero) for unlimited.
Live stats
While a server runs, Cube samples CPU and memory a few times a second and plots them on the Resources plane. CPU is shown as a percentage of one core (200% means two full cores). The world directory's on-disk size is shown alongside and grows as the map is explored.