Performance Metrics

The Common Metrics selected /used during the capacity planning is as below

· Response time
· Turnaround time = the time between the submission of a batch job and the completion of its output.
· Stretch Factor: The ratio of the response time with single user to that of concurrent users.
· Throughput: Rate (requests per unit of time) Examples:
o Jobs per second
o Requests per second
o Millions of Instructions Per Second (MIPS)
o Millions of Floating Point Operations Per Second (MFLOPS)
o Packets Per Second (PPS)
o Bits per second (bps)
o Transactions Per Second (TPS)
· Capacity:
o Nominal Capacity: Maximum achievable throughput under ideal workload conditions. E.g., bandwidth in bits per second. The response time at maximum throughput is too high.
o Usable capacity: Maximum throughput achievable without exceeding a prespecified response-time limit
· Efficiency: Ratio usable capacity to nominal capacity. Or, the ratio of the performance of an n-processor system to that of a one-processor system is its efficiency.
· Utilization: The fraction of time the resource is busy servicing requests.
· Average Fraction used for memory.