The overall speed of a computer depends on the performance of its individual components, chiefly the processor, memory and video card. These computer parts should be upgraded together to boost the computer's speed, as partial upgrades may only introduce negligible improvements.
These three components each play a different role in performance. The processor, which is the central part of any computer, is responsible for executing instructions. Its performance is measured by its clock speed and the number of cores. The size and speed of the system memory and storage disk affect how fast the computer can read, write and transfer data. The video card helps render the graphics displayed on the screen. More powerful cards are able to support higher screen resolutions.