When comparing the differences between DDR3 and DDR4, there are quite a few significant differences to be seen. Of course, the first major distinction is in the speed. The fastest type of memory for a computer is generally DDR4. DDR3 is the slower of the two, but it is also the most popular as it has a broader user base. DDR4 and DDR5 RAMs are yet to be launched as the launch by the major RAM manufacturing companies has been delayed to COVID-19 lockdowns.