An M.2 SSD is ideal for small form factor computers that need a boost in performance. These drives are compact, do not require cable connections, and are known for their fast data transfer speeds, making them a superior choice for a compact desktop designed for enhanced performance. A standard PCIe SSD is also fast but generally larger and may not fit the physical constraints. An mSATA SSD, though compact, is not as commonly used in newer systems and is often outperformed by M.2 models. Finally, a 3.5-inch SSD is larger and typically not designed to fit in the limited space of a compact desktop chassis.