1- Suppose that the processor has access to 3 levels of memory. Level 1 contains 1000 words and has an access time of 0.01 us; level 2 contains 10,000 words and has an access time of 0.1 us; level 3 contains 100,000 words and has an access time of 1 µs. Suppose 80% of the memory accesses are found in level 1, 15% of the memory accesses are found in level 2, 5% of the memory accesses are found in level 3, then find the average access time ?

Consider a virtual memory system with the following characteristics for accessing memory: 1 nanosecond for a read operation with a hit in cache 5 nanoseconds for a read operation with a miss in cache 2 nanoseconds for a write operation with a hit in cache 10 nanoseconds for a write operation with a miss in cache The cache hit ratio is 0.9   If a sequence of instructions were executed: 100 instruction fetch operations, 60 memory operand read operations, and 40 memory operand write operations, what would be the average memory access time (in nanoseconds) in executing the sequence of instructions:

Assume miss rate of an instruction cache is 2% and miss rate of data cache IS 4%, If a processor have CPI of 2 without any memory stalls and miss penalty is 100 cycles for all misses, determine how much faster a processor would run with a perfect cache that never missed. Assume frequency of all loads and stores is 36%.