How fast will my restores be?
To determine restore performance, you must measure how fast data can be
read reads from tape and how fast data can be written to disk. Restore
performance will be the slower of these two measurements.
Device Performance test
Use the System Performance Restore Pre-test to measure the
speed of the disk subsystem.
Note this test is independent of the backup application and uses test restore
data. Please check with your backup vendor if actual backup performance is
to measure the speed of the tape