Complex sentence: PRAM is one of a number of new memory technologies that are attempting to compete in the non-volatile role with the almost universal Flash memory, which has a number of practical problems these replacements hope to address.
Split into simpler sentences: PRAM is one of a number of new memory technologies that are attempting to compete in the non-volatile role with the almost universal Flash memory. The latter technology which has a number of practical problems which these replacements hope to address.