Retrospect: How To Interpret Performance Shown in Log

Please clarify the way Dantz Development Corporation's Retrospect software computes its throughput in this example:

8:56:53 AM: Copying
8:57:00 AM: Comparing
8:57:04 AM: Execution completed successfully

Total Completed: 31 files, 861 KB
Performance: 4.5 MB/minutes (7.2 copy, 12.6 compare)
The log gives the impression that the copy took 7.2 seconds and the compare took 12.6 seconds. This is not correct. These times are instead accumulative. In other words, after 7.2 seconds the copy was completed and after 5.4 more seconds the compare was completed.

Here are the calculations used to get the number above:

Duration: 00:00:11
Throughput = kbytes backed up / duration
4.5 MB/minute = 861 KB/11 sec * 60 sec / 1 minute * 1 MB/1000 KB
7.2 MB/minute = 861 KB/7.2 sec * 60 sec / 1 minute * 1 MB/1000 KB
9.9MB/minute = 861 KB/5.2 sec * 60 sec / 1 minute * 1 MB/1000 KB

Note: The total performance is based on the total time of the backup and compare procedures. If you compute just backup or compare time, you seem to have a higher throughput.

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Published Date: Feb 19, 2012