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Moreover, DRMS is quite expensive. However, it is fast but still, DRMS is not enough for CPUs. DRMS works on electricity. Hence if power is cut that time data is not accessible. Furthermore, SRAM is very fast and smaller but expensive. SRAM memory used in cache. So, the first CPU finds data from the cache and if data is not in the cache, then the CPU starts to find it in the main memory and tries until it finds that data. So, this data transfers into the cache. This transfer works in two ways. The first way is that the same data is transferred into the cache for a short period of time and this is known as temporal locality. Another one is a spatial locality and this method also accessed nearby locations if it will be needed.