Operating a rotatable media storage device at multiple spin-speeds

Abstract

A rotatable media storage device operates using multiple disk spin-speeds, e.g., a reduced spin-speed and a nominal spin-speed. A disk is spun up to a reduced spin-speed and an initial data transfer is began while the disk spins at the reduced spin-speed, if an amount of work that has been requested is below a threshold. The disk is spun up to a further spin-speed (e.g., a nominal spin-speed), which is greater than the reduced spin-speed, and the initial data transfer is began while the disk spins at the further spin-speed, if the amount of work that has been requested is above the threshold. Alternative embodiments using multiple disk spin-speeds are also provided.

1 . In a data storage device including a disk, a method for controlling a spin-speed at which an initial data transfer occurs after the disk begins to spin-up from rest, the method comprising: 
 (a) spinning the disk up to a reduced spin-speed and beginning to perform the initial data transfer while the disk spins at the reduced spin-speed, if an initial amount of work that has been requested is below a threshold; and    (b) spinning the disk up to a further spin-speed, which is greater than the reduced spin-speed, and beginning to perform the initial data transfer while the disk spins at said further spin-speed, if the initial amount of work that has been requested is above said threshold.    
   
   
       2 . The method of  claim 1 , wherein the initial amount of work is defined at least in part by an initial amount of data to be transferred.  
   
   
       3 . The method of  claim 1 , wherein the initial amount of work is defined at least in part by an estimated amount of time necessary to complete the work.  
   
   
       4 . The method of  claim 1 , wherein the data transfer includes at least one of reading data from the disk and writing data to the disk.  
   
   
       5 . The method of  claim 1 , wherein said further spin-speed comprises a nominal spin-speed.  
   
   
       6 . The method of  claim 5 , further comprising: 
 (c) spinning the disk up from said reduced spin-speed to said nominal spin-speed, if additional work is requested while the initial data transfer is being performed at said reduced spin-speed.    
   
   
       7 . The method of  claim 5 , further comprising: 
 (c) spinning the disk up from said reduced spin-speed to said nominal spin-speed, if additional work above said threshold is requested while the initial data transfer is being performed at said reduced spin-speed.    
   
   
       8 . The method of  claim 5 , further comprising: 
 (c) spinning the disk up from said reduced spin-speed to said nominal spin-speed, if additional work above a further threshold is requested while the initial data transfer is being performed at said reduced spin-speed.    
   
   
       9 . The method of  claim 5 , wherein: 
 (c) spinning the disk up from said reduced spin-speed to said nominal spin-speed, if enough additional work is requested that a total amount of work exceeds said threshold while the initial data transfer is being performed at said reduced spin-speed.    
   
   
       10 . The method of  claim 6 , wherein step (c) includes performing an additional data transfer at said nominal spin-speed.  
   
   
       11 . In a data storage device including a disk, a method for controlling a spin-speed at which an initial data transfer occurs, between a host and the disk of the data storage device, after the disk begins to spin-up from rest, the method comprising: 
 (a) spinning the disk up to one of a plurality of different spin-speeds at which the data storage device can operate, as instructed by the host; and    (b) beginning to perform a data transfer at said instructed spin-speed.    
   
   
       12 . The method of  claim 11 , wherein the plurality of spin-speeds include a nominal spin-speed and a reduced spin-speed that is less than said nominal spin-speed.  
   
   
       13 . In a data storage device including a disk, a method for controlling a spin-speed at which an initial data transfer occurs after the disk begins to spin-up from rest, the method comprising: 
 (a) spinning the disk up to a reduced spin-speed and performing an initial data transfer while the disk spins at said reduced spin-speed; and    (b) spinning the disk up to a nominal spin-speed, which is greater than said reduced spin-speed, and performing an additional data transfer while the disk spins at said nominal spin-speed.    
   
   
       14 . In a data storage device including a disk, an actuator assembly having a head for reading from and/or writing to the disk, and a load/unload ramp on which to park the head, a method for reducing the amount of time it takes for a head to begin reading from and/or writing to the disk after the actuator assembly has been parked on the load/unload ramp, the method comprising: 
 (a) monitoring a disk spin-speed as the disk is spinning up to a selected spin-speed;    (b) beginning a ramp load operation before the disk spin-speed reaches said selected spin-speed, but such that the disk will achieve said selected spin-speed prior to the head reaching an outer diameter of the disk; and    (c) performing an initial data transfer at said selected spin-speed.    
   
   
       15 . The method of  claim 14 , further comprising: 
 (d) adjusting said spin-speed and performing a further data transfer at said adjusted spin-speed.    
   
   
       16 . The method of  claim 14 , wherein said selected spin-speed comprises a nominal spin-speed.  
   
   
       17 . The method of  claim 14 , wherein said selected spin-speed comprises a reduced spin-speed that is less than a nominal spin-speed.  
   
   
       18 . The method of  claim 14 , wherein said selected spin-speed is selected from a nominal spin-speed and a reduced spin-speed that is less than said nominal-spin speed.  
   
   
       19 . The method of  claim 14 , further comprising the step of receiving an instruction, from a host, said instruction informing the disk drive of said selected spin-speed.  
   
   
       20 . The method of  claim 14 , further comprising selecting a spin-speed based on a comparison of the initial data transfer to a threshold.  
   
   
       21 . The method of  claim 20 , wherein said threshold is defined by a host.