CPI Execution: Average Memory Access Time (AMAT)

CPIStall = (MemAccess/Instruction)(MemStall) = (1 + %load + %store)(1 – hi)(Mi)

CPI = CPIPerfect + CPIStall, and in the ideal case, CPIStall = 0, so CPI = CPIPerfect

AMAT = 1 + MemStall, where MemStall = (Miss Rate)(Miss Penalty)

<p>Speedup = CPI/CPIPerfect, where CPI = CPIPerfect in the ideal case</p> Signup and view all the answers

<p>The miss rate is 1, resulting in MemStall = (1)(Miss Penalty)</p> Signup and view all the answers

<p>CPI = CPIPerfect + CPIStall = 1.1 + 140 = 141.1</p> Signup and view all the answers

<p>The number of cycles required to complete an average memory access request by the CPU.</p> Signup and view all the answers

<p>AMAT = ti + (mi)(T2) or AMAT = 1 + (mi)(T2) since ti = 1.</p> Signup and view all the answers

<p>MemStall represents the memory stall cycles per memory access, and it is equal to (m1)(T2) or (Miss Rate)(Miss Penalty). AMAT is directly affected by MemStall, with the formula AMAT = 1 + MemStall.</p> Signup and view all the answers

<p>The miss rate (mi) is equal to 1 – hi, indicating that the sum of the hit rate and miss rate is always equal to 1.</p> Signup and view all the answers

<p>A higher miss rate leads to a higher AMAT, as it increases the number of stall cycles added to the CPU execution cycles for one memory access.</p> Signup and view all the answers