How did transistors overcome the size and power-use problems of vacuum tubes?

Transistors overcame the limitations of vacuum tubes by utilizing semiconductor materials rather than relying on thermionic emission, which required a heated cathode to generate electrons.12

The primary differences that allowed transistors to solve size and power issues include:

• No Heating Required: Unlike vacuum tubes, which must be heated to operating temperatures to function, transistors operate at room temperature. This eliminates the need for power-hungry heating elements, significantly reducing overall power consumption and heat generation.13
• Physical Size: Transistors are inherently small, solid-state devices. Because they do not require the bulky glass or metal-ceramic enclosures necessary to maintain a vacuum, they can be packed into much smaller spaces than comparable vacuum tubes.431
• Efficiency and Reliability: By avoiding the thermal fatigue associated with the repeated heating and cooling of vacuum tubes, transistors offer higher reliability. Their low power requirements and compact nature enabled the miniaturization of complex circuitry, eventually leading to the development of integrated circuits.32

While vacuum tubes remain superior for specific high-power or high-frequency applications, the transistor's efficiency made it the ideal replacement for most low-voltage electronic circuits.51