Give two reasons why caches ar

Caches are useful when two or more components need to exchange data,and the components perform transfers at differing speeds.Caches solve the transfer problem by providing a buffer of intermediate speed between the components.If the fast device finds the data it needs in the ***,it need not wait for the slower device.The data in the *** must be kept consistent with the data in the components.If a component has a data value change,and the datum is also in the ***,the *** must also be updated.This is especially a problem on multiprocessor systems where more than one process may be accessing a datum.A component may be eliminated by an equal-sized ***,but only if:(a) the *** and the component have equivalent state-saving capacity (that is,if the component retains its data when electricity is removed,the *** must retain data as well),and (b) the *** is affordable,because faster storage tends to be more expensive.