Upgrade the memory in your compatible NAS server with the 4GB DDR4 2666 MHz Non-ECC SO-DIMM Memory Module from Synology. This single RAM module features a capacity of 4GB, a clock speed of 2666 MHz (PC4-21300), and a SO-DIMM form factor. It is unbuffered and does not use ECC technology. Adding more memory to your system will help boost its capabilities, including improving system performance and application responsiveness. Start-up times will be improved with fewer delays during routine operations and more programs will be able to run simultaneously with easier switching between them.