Sony PCG FX Series laptops use unbuffered, non-ECC, non-registered memory. The SO-DIMM chips are small, yet powerful. SO-DIMM chips are half the size of DIMMs, but provide the same level of performance, speed and capacity. The laptops use SDRAM, which stands for synchronous dynamic random access memory. It's a type of memory that is synchronized with the system's bus, allowing it to respond quickly to changes in control inputs. The chips have divided storage areas, allowing them to work on multiple commands at once.