Response Times: Rough Guide

Definition

The following times provide you with an overview of the optimal response times in your SAP system. You can display the current workload overview for your system with the workload monitor.

Proportions of the Response Time

Performance Data	Time
Average response time	Around 1 second (dialog), < 1 second (update)
Average CPU time	Around 40% of the average response time
Average wait time	< 1% of the average response time
Average load time	< 10% of the average response time
Average database time per dialog step	Around 40% of the average response time

Note

The operating system can affect these values by up to around 10%.

The ratio of the CPU time to the total time should not fall under 5%. A smaller proportion could mean that there is an input/output bottleneck or that a database overload has caused long wait times.

The average response times for dialog transactions (online transactions) should not be more than a second, since a higher value would strain the patience of the user too much.

Times for Database Access

Database Access	Time
Direct read	< 10 ms
Sequential read	< 40 ms
Changes	> 25 ms

Possible Causes of Bad Response Times

High Value For	Possible Causes
DB request (Change/Comm.)	Problems with database or index
Load time	Buffer too small Transports to the productive system
Wait time	Insufficient work processes Inactive update Incorrect operation mode Locked tasks Long-running transactions

Note

In a database system that is functioning properly, the times for direct reads and changes should not be more than 10 milliseconds.

The time for sequential reads should not be more than 30-40 milliseconds.

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