Increase memory capacity in a compatible DURABOOK S15 Plus computer to 64 GB. Higher installed memory capacity provides more room for applications and active data to remain in system memory, which is relevant when the system is used with large files, multiple concurrent applications, virtualized workloads, or memory-intensive technical software. RAMUP-64G-S15-PLUS is specifically assigned to the S15 Plus platform rather than serving as a general-purpose memory selection. That platform association matters when matching an upgrade to an existing computer: memory components must correspond to the intended system configuration, not merely meet a target capacity. This upgrade supplies the stated 64 GB capacity for the designated DURABOOK system. Choose this upgrade where the S15 Plus deployment requires a 64 GB RAM configuration. It is an expansion component for an existing compatible computer, not a complete computer system. The product is distinguished within the S15 Plus memory-upgrade range by its stated 64 GB capacity and its platform-specific designation. It provides a direct path to the higher memory configuration without changing the base computer platform.