AMAT
Is average memory access time
AMAT= hit time+miss rate×miss penalty
=0.6+0.02×90
=0.6+1.8
=2.4 ns
6. Calculate AMAT, when hit time is 0.6ns, miss rate is 0.02 and miss penalty is...
AMAT = Time for a hit + (Miss rate x Miss penalty) For a data cache with a 4% miss rate and a 5-cycle hit latency, calculate the average memory access time (AMAT). Assume that latency to memory and the cache miss penalty together is 100 cycles. Note: The cache must be accessed after memory returns the data.
(a) Given a 100 MHz machine with a with a miss penalty of 20 cycles, a hit time of 2 cycles, and a miss rate of 5%, calculate the average memory access time (AMAT). (b) Suppose doubling the size of the cache decrease the miss rate to 3%, but causes the hit time to increases to 3 cycles and the miss penalty to increase to 21 cycles. What is the AMAT of the new machine?
a) Calculate the AMAT for a cache system with one level of cache between the CPU and Main Memory. Assume that the cache has a hit time of 1 cycle and a miss rate of 11%. Assume that the main memory requires 300 cycles to access (this is the hit time) and that all instructions and data can be found in the main memory (there are no misses). b) Let us modify the cache system from part (a) and add...
(a)What is the average memory access time (AMAT) if a cache uses write-back strategy and 20% of the data blocks to be swapped out are dirty. Assume that the miss rate is 15%, the hit time of the cache is 1 cycle and the miss penalty is 8 cycles for the data blocks that are not dirty and 20 cycles for those blocks that are dirty. (b) What is the speedup up if we add a “write-buffer” that eliminates 40%...
Assume an memory hierarchy with unified data and instruction memories, miss rate equal to 15%, miss penalty equal to 90 cycles, 25% Load/Store instructions, TLB miss ratio per TLB access equal to 6% and TLB miss penalty equal to 80 cycles. What is the realistic CPI of this system if the ideal CPI is 1.5? What is the speedup compared to not having TLB? What would be the speedup if the TLB could hold every entry?
3. 12+2-4 points] We are comparing the two caches in Problem 1 and Problem 2. Suppose both caphes have a hit time of 2 cycles. The cache in Problem 1 has a miss penalty of 15 cycles. The one in Problem 2 has a miss penalty of 25 cycles. Calculate the total time taken (in cycles) for all accesses, for each cache. Which cache is better- the one in Problem 1 or Problem 2? 3. 12+2-4 points] We are comparing...
Assume the miss rate of an instruction cache is 3% and the miss rate of the data cache is 5%. If a processor has a CPI of 2 without any memory stalls and the miss penalty is 120 cycles for all misses, determine how much faster a processor would run with a perfect cache that never missed. Assume the frequency of all loads and stores is 36%. *The size of the tag field-64- (n + m 2). ** The total...
Suppose you have a machine with separate I- and D- caches. The miss rate on the I-cache is 2.6% , and on the D-cache 3.8%. On an I-cache hit, the value can be read in the same cycle the data is requesfed. On a D-cache hit, one additional cycle is required to read the value. The miss penalty is 100 cycles for data cache, 150 for I-cache. 40% of the instructions on this RISC machine are LW or SW instructions,...
Compare two designs of a computing system. (i) 1KB L1 cache with misss-rate of 11% and hit-time of 0.62ns. (ii) 2KB L1 cache with miss-rate of 8% and hit-time of 0.66ns . For both the main memory access takes 80ns. (a) Assuming that the L1 hit-time determines the processor cycle time, what are the clock frequencies of the two designs? (b) Calculate the Average Memory Access Time (AMAT) for the two designs
Miss rate is 3%. An 4. For a given application, 30% of the instructions require memory access instructio L1 miss penalty is 70 clock cycles. Calculate the average memory access time n can be executed in one clock cycle. L1 cache access time is approximately 3 clock cycles while t ro tnctruction renuire 1.2 ms.