The compact nature of laptops requires a number of internal components to fit in a small amount of space. The size restrictions result in a variety of form factors for a number of laptop components, such as the system board, RAM, and CPU. Some laptop components, such as the CPU, may be designed to use less power to ensure that the system can operate for a longer period of time when using a battery source.


Desktop motherboards have standard form factors. The standard size and shape allow motherboards from different manufacturers to be interchangeable. In comparison, laptop motherboards vary by manufacturer and are proprietary. When you repair a laptop, it is recommended that you obtain a replacement system board from the laptop manufacturer. Figure 1 shows a comparison between a desktop motherboard and a laptop motherboard.

Laptop system boards and desktop motherboards are designed differently. Components designed for a laptop generally cannot be used in a desktop. Laptop and desktop designs are compared in Figure 2.


Laptops have space restrictions. Therefore, they use Small Outline Dual In-line Memory Modules (SODIMMs), as shown in Figure 3.


Laptop processors are designed to use less power and create less heat than desktop processors. As a result, laptop processors do not require cooling devices that are as large as those found in desktops. Laptop processors also use CPU throttling to modify the clock speed as needed to reduce power consumption and heat. This results in a slight decrease in performance, but it increases the lifespan of some components. These specially designed processors allow laptops to operate for a longer period of time when using a battery power source.

NOTE: Refer to the laptop manual for compatible processors and for replacement instructions.