Success! Adding 2 x 8GB RAM to my TS-451+. TrueNAS is running way better with the additional RAM. 8GB was enough just for basic file sharing but it did run into issues
Storage Qnap de 9 baias TS-963X-2G Processador Quad-Core 2.0GHz, 2GB de memória RAM (expansível até 16GB) – Storage Brasil
QNAP TS-451+ NAS (4 jedrni procesor, 16GB RAM)
16GB Kit (2x8GB) für QNAP TS TS-451 SO-DIMM, 55,20 €