You already know what the difference a laptop and a desktop computer is. One is mobile, compact, with an all-in-one keyboard and monitor design that folds up and packs away like a notebook. The other is a tower setup, with a monitor that sits on a desktop and a tower that sits beside it or on the floor. But they both have similar performance and functionality, and even come at similar price points. So, what’s the difference in the hardware between a laptop and a desktop? Here’s a general breakdown.

Laptop Hard Drives

Laptop hard drives measure up at 2.5-inches while desktop hard drives are usually 3.5-inches. Furthermore, desktop hard drives usually have disk speeds of 7,200 RPM while laptop hard drives have speeds of 5,200 RPM. The actual difference in performance is negligible, for most users. What matters more is the power consumption. Like most laptop components, laptop hard drives use less power, and thus drain battery life less quickly.

Another popular option for laptop hard drives are solid state drives. These are flash-based drives that use a similar technology as SD cards. There are no moving parts, meaning they are less susceptible to physical defects and they are much quieter. However, they are far more expensive.

Laptop RAM

RAM, or random access memory, is used as a memory cache for faster multi-tasking and application processing. Desktop RAM comes in a dual in-line memory module (DIMM). Laptop RAM is smaller, and comes in SO DIMM (small outline DIMM) form factors. They’ll still be the same denominations--1 GB, 2 GB, etc. and they have the same functions.

Laptop Power Supplies

Desktop computers have internal power supplies. They also usually come with fans and/or heat sinks to keep the rest of the tower cool. Laptop power supplies are external and are part of the power cord. They are the “brick” part of your power cord. These are specifically designed for the laptop that they are shipped with. Using a different laptop power supply can cause damage to your computer. Because laptop power supplies are external, they do not need to be cooled.

Laptop Graphics Cards

Laptops, if they have graphics cards at all, have graphic chips integrated into the motherboard. They won’t usually have a dedicated unit with its own memory, like desktops do. Integrated graphics cards are less powerful and cannot be upgraded by the end user.

Laptop Processors

Laptop processors are usually dual-core or quad-core. They will usually be optimized for less power consumption and smaller form factor. Usually, CPU manufacturers will have separate lines for moible CPUs, such as the Intel Atom series or the Celeron M Series. Laptop CPUs will usually be advertised as “low voltage” or “ultra low voltage.”

Nettops and Slim Desktop Towers

With all that being said. you won’t usually find desktop parts in a laptop, but you can find mobile optimized hardware in a desktop. These so-called nettops or slim desktops computers are ideal for their low profile, their quietness and their low power consumption. These make great “always on” home thearter PCs, multimedia servers or backup units.