All the below recommendations assume the TrueNAS System in question is not used for anything other than running Apps and Storage. Adding VMs or busy shares will significantly increase the requirements.
Minimal system Specifications
Systems complying with these minimal specifications will be able to run some Apps and just a few at the same time. Experiences in terms of performance and which Apps work may vary.
CPU: 4 Cores RAM: 16GB GPU: None Storage: 250GB HDD Pool storage + OS Storage
recommended System Specifications
Systems complying with these recommended specifications, will be able to run (almost) any App we offer and many at the same time, depending on system load.
CPU: 8 Cores RAM: 32GB GPU: Intel iGPU Storage: 1TB HDD Pool storage + Metadata/smallblock vdev + OS Storage