What’s the difference between DIMM and SO-DIMM memory? DIMM and SO-DIMM represent two different physical sizes of memory. We're talking two 16GB modules running at 2666MHz (that's PC4-21300/PC4-2666V for you tech-savvy folks). Perfect for compatible laptops, notebooks, and all-in-one computers that need a serious performance boost. This NON-ECC unbuffered memory comes in either single or dual rank (1Rx8 or 2Rx8) and runs at the standard DDR4 1.2V If the memory is faster than your system allows, it will automatically downclock to that max speed, meaning it's safe to buy faster memory. 2666MHz Memory Kit 16GB (2x8GB) DDR4 2666MHz SODIMM Laptop RAM Kit - 260-Pin, PC4-21300 Ram Ddr4 NON-ECC Unbuffered; 2Rx8 (Dual Rank x8); JEDEC DDR4 standard 1., 2V This is a 16GB DDR4 2666MHz SODIMM (260-Pin) RAM module, compatible with ASUS TUF FX505/FX505GT laptops, and is non-ECC unbuffered A-Tech provides a Lifetime... A-Tech DDR4 Memory RAM compatible replacement for CT2K16G4SFD8266 Each memory type uses different slot designs, voltages, and architectures, so your system must support the memory type specifically. What does Non-ECC mean and do I need ECC memory instead? Non-ECC (non-error correcting) memory is required for most laptops and desktops. How do I know which speed to choose? Each system has its own max supported speed. If your system doesn’t mention ECC support, you need Non-ECC. They are not interchangeable. Single 16 GB Module; DDR4 SO-DIMM 260-Pin; Speeds up to 2666/2667-MHz, PC4-21300 (PC4-2666V) ECC is typically only used in servers or workstations and is not interchangeable with Non-ECC memory. 16gb Ddr4 Laptop Ram Sodimm A-Tech 32GB (2x16GB) RAM Replacement For CT2K16G4SFRA32A | DDR4 3200MHz A-Tech RAM Replacement For Crucial DIMM is the larger type used in standard desktop computers. All A-Tech memory modules undergo stringent quality control testing to ensure dependable and reliable performance