Two types of RAM, static and dynamic, are available. Both types feature advantages and disadvantages in regards to speed, costs and actual size of the RAM modules. While there are devices that use static RAM exclusively, most computers use a combination of both types of RAM to exploit the benefits and minimize the limitations of both.
A computer with static RAM holds the advantage in speed. It is quicker than a computer with dynamic RAM. Static RAM does not use capacitors and does not need to continuously access its memory. Because there is no need to access all the information like dynamic RAM does, static RAM is much faster. Also, because static RAM does not access information continuously it is more energy-efficient than dynamic RAM.
A disadvantage of a computer with static RAM is that the RAM takes up a lot of physical space. A static RAM chip needs four to six transistors to store a bit of information. A dynamic RAM chip needs only one transistor. Creating a static RAM module of 32 MB or larger would become prohibitive because the static RAM module would be so large.
A computer with static RAM would cost more than a computer with dynamic RAM. Because the static RAM needs four to six transistors to store a bit of information and the dynamic RAM only needs one, it costs more to make a 32 MB static RAM module than a 32 MB RAM module.