Approximately how fast do disks, CDs, MP3s, DVDs etc. spin?
Approximately how fast do hard drives spin?
Discs - approx. 500 on the inside and 200 rpm on the outside.
Hard drives - About 5400 to 12000+ rpm.
Most CDs and DVDs use CLV (Constant Linear Velocity).
The RPM changes so that the Data Transfer Rate can remain the same.
DVDs spin at 1530 rpm when reading at the innermost (starting) edge,
and slow down to 630 rpm when reading the outermost edge (end)
CDs also start at the innermost edge
Those are for standard 1x speed
and mutiply for speeds up to about 12x.
Over 12x speed, then they usually use CAV (Constant Angular Velocity), the RPM speed doesn't vary, but then the Data Transfer Rate does.