If you have 21 disks and 21 machines, how much slower is this install method than if you had 21^2 disks for 21 machines? Assuming all disks read in equal time

If you have 21 disks and 21 machines, how much slower is this install method than if you had 21^2 disks for 21 machines? Assuming all disks read in equal time and it takes no time to move the disks.