What determines the capacity and space available in a PCIe expansion card?

The capacity and space available in a PCIe expansion card are primarily determined by form factors. Form factors refer to the physical sizes, shapes, and specifications of the expansion card, which dictate how many components can be integrated onto the card, as well as their layout. Different form factors, such as PCIe x1, x4, x8, or x16, indicate the number of lanes available for data transfer, which in turn affects the performance and capacity for additional features or components on the card.

While type of RAM, operating system, and cooling systems are important considerations in the overall functionality or performance of a computer system, they do not directly influence the physical space or the capacity available on a PCIe expansion card. Type of RAM is related to the main memory of the system rather than the structure of the expansion card itself. The operating system manages the utilization of hardware resources but does not affect the physical design or capacity of expansion cards. Cooling systems are essential for maintaining optimal operating temperatures but do not determine the inherent capacity of the cards. Thus, form factors are the key aspect that defines the design and limitations of PCIe expansion cards.