Qnap RAM4GDR4ECP0UD2666 RAM Module, Memory Size 4 GB, Memory DDR4 SDRAM, Memory Voltage 1.20 V, Speed 2666 MHz, ECC, Unbuffered, NAS Server, Number of Pins-288, Form Factor DIMM. The QNAP RAM-4GDR4ECP0-UD-2666 is designed for their TS-x83XU series, the 4GB DDR4 2666 MHz UDIMM ECC Memory Module from QNAP is a single RAM module that will let you upgrade the overall memory capacity of your compatible NAS.