Computer running slowly? Adding more computer memory, also known as Random-Access Memory (RAM), can help speed things up. If you want to improve your computer’s multitasking capability and increase its start-up speed, installing extra computer memory is a simple, cost-effective solution. DDR3, features four clock speeds: 1333Mhz, 1600Mhz, 1866Mhz, and 2133Mhz. DDR4 is the latest model, and provides a greater range of clock speeds and timings, lower power consumption, as well as reduced latency.