Dbms_resource_manager.calibrate_io question on Number of Disks

I run the calibrate_io on a VM on a laptop to test it, against 18.3 database.

The laptop has 1 physical disk. O/S RedHat

I run it as following:

Declare

Calc_lat number;

Calc_iops number;

Calc_mbps number;

Begin

Dbms_resource_manager.calibrate_io(1,10, Calc_iops, Calc_mbps, Calc_lat);

Dbms_output.put_line('Max IOPS : '||Calc_iops);

Dbms_output.put_line('Max mbytes-per-sec: '||Calc_mbps);

Dbms_output.put_line('Calc. latency : '||Calc_lat);

End;

/

I have entered number of Physical Disks=1. Oracle says that entering this value correctly will help calibrate_io get better results.