Memory RAM Upgrade for QNAP NAS TS-451 4GB DDR3 SODIMM | eBay
How To: Upgrade QNAP TS-451+ NAS To 16GB RAM – andy.ph
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