Which factor does NOT affect CPU speed?

The factor that does not affect CPU speed is touchscreen capability. This feature pertains more to the input and interaction capabilities of a device rather than the processing power of the CPU itself. CPU speed is primarily influenced by several technical specifications that dictate how efficiently and quickly the processor can perform tasks.

Clock speed refers to the frequency at which a CPU can execute instructions, measured in GHz, and directly impacts the number of operations the CPU can perform in a given time. Word length, which defines the amount of data a CPU can handle in one operation, also affects the processing capabilities, especially in tasks requiring large data manipulation. Bus width is another critical factor, as it determines the amount of data that can be transferred to and from the CPU in parallel, influencing overall system performance.

In contrast, touchscreen capability is an accessory feature relevant for user interaction with devices rather than a technical component that enhances or limits processing speed. It does not influence how quickly the CPU can execute its core functions.