Qnap Accessories (Ram-4GDR4A0-SO-2400), 4 GB, DDR4 SDRAM, 1.20 V, Speed 2400 MHz, DDR4-2400/PC4-19200, 260-pin, Form Factor SoDIMM. The 4GB DDR4 2400 MHz SO-DIMM Memory Module from QNAP is a single RAM module that will let you upgrade the overall memory capacity of the TVS-951X. It features a capacity of 4GB, a clock speed of 2400 MHz (PC4-19200).