Data storage device seeking multiple actuators to improve performance
A data storage device is disclosed comprising a plurality of disk surfaces, a first plurality of heads actuated over a first subset of the disk surfaces by a first actuator, and a second plurality of heads actuated over a second subset of the disk surfaces by a second actuator. A first access command is executed using the first actuator and a second access command is executed using the second actuator. When the first access command finishes before the second access command finishes, a third access command is selected to execute using the first actuator based on a time remaining (To 2 ) to finish the second access command, and at least part of the second access command is executed while concurrently executing at least part of the third access command during To 2.
1. A data storage device comprising:
a plurality of disk surfaces;
a first plurality of heads actuated over a first subset of the disk surfaces by a first actuator;
a second plurality of heads actuated over a second subset of the disk surfaces by a second actuator; and
control circuitry configured to:
receive a plurality of access commands, wherein each access command is associated with one of the heads;
execute a first access command using the first actuator and execute a second access command using the second actuator;
when the first access command finishes before the second access command finishes, select a third access command to execute using the first actuator based on a time remaining (To 2 ) to finish the second access command; and
execute at least part of the second access command while concurrently executing at least part of the third access command during To 2 .
2. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to select the third access command based on k·To 2 , where k is a predetermined scalar.
3. The data storage device as recited in claim 2 , where decreasing k increases a throughput and increases a power consumption of the data storage device.
4. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to select the third access command by generating a seek profile for the first actuator based on To 2 .
5. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to concurrently seek the first actuator and the second actuator during at least part of To 2 .
6. The data storage device as recited in claim 5 , wherein while concurrently seeking the first and second actuators the control circuitry is further configured to:
seek the second actuator based on a first seek profile; and
seek the second actuator based on a derated version of the first seek profile.
7. The data storage device as recited in claim 1 , wherein:
the data storage device operates according to a performance threshold exhibited when waiting to execute the third access command until after the second access command finishes; and
the control circuitry is further configured to select the third access command based on To 2 in a manner that ensures a performance of the data storage device does not fall below the performance threshold.
8. A data storage device comprising:
a plurality of disk surfaces;
a first plurality of heads actuated over a first subset of the disk surfaces by a first actuator;
a second plurality of heads actuated over a second subset of the disk surfaces by a second actuator; and
control circuitry configured to:
receive a plurality of access commands, wherein each access command is associated with one of the heads; and
concurrently execute at least part of a second access command using the second actuator and at least part of a third access command using the first actuator, wherein:
the data storage device operates according to a performance threshold exhibited when serially executing the second access command and the third access command; and
the control circuitry is further configured to concurrently execute at least part of a second access command and at least part of the third access command using a first seek profile for the first actuator and a second seek profile for the second actuator that ensures a performance of the data storage device does not fall below the performance threshold.
9. The data storage device as recited in claim 8 , wherein the control circuitry is further configured to:
execute a first access command using the first actuator and execute the second access command using the second actuator;
when the first access command finishes before the second access command finishes, select the third access command to execute using the first actuator based on a time remaining (To 2 ) to finish the second access command; and
execute at least part of the second access command while concurrently executing at least part of the third access command during To 2 .
10. The data storage device as recited in claim 9 , wherein the control circuitry is further configured to select the third access command based on k·To 2 , where k is a predetermined scalar.
11. The data storage device as recited in claim 10 , where decreasing k increases a throughput and increases a power consumption of the data storage device.
12. The data storage device as recited in claim 9 , wherein the control circuitry is further configured to select the third access command by generating the first seek profile for the first actuator based on To 2 .
13. The data storage device as recited in claim 9 , wherein the control circuitry is further configured to concurrently seek the first actuator and the second actuator during at least part of To 2 .
14. The data storage device as recited in claim 13 , wherein the second seek profile is a derated version of the first seek profile.
15. The data storage device as recited in claim 8 , wherein the second seek profile is a derated version of the first seek profile.
16. A data storage device comprising:
a plurality of disk surfaces;
a first plurality of heads actuated over a first subset of the disk surfaces by a first actuator;
a second plurality of heads actuated over a second subset of the disk surfaces by a second actuator; and
a means for receiving a plurality of access commands, wherein each access command is associated with one of the heads;
a means for executing a first access command using the first actuator and executing a second access command using the second actuator;
when the first access command finishes before the second access command finishes, a means for selecting a third access command to execute using the first actuator based on a time remaining (To 2 ) to finish the second access command; and
a means for executing at least part of the third access command while concurrently executing at least part of the second access command during To 2 .
17. The data storage device as recited in claim 16 , wherein the third access command is selected based on k·To 2 , where k is a predetermined scalar.
18. The data storage device as recited in claim 17 , where decreasing k increases a throughput and increases a power consumption of the data storage device.
19. The data storage device as recited in claim 17 , further comprising a means for configuring k based on at least one of:
a power or performance target for the data storage device; or
a queue depth of a command queue for storing the access commands.
20. The data storage device as recited in claim 17 , further comprising a means for adapting k based on at least one of:
a power or performance target for the data storage device; or
a queue depth of a command queue for storing the access commands.
21. The data storage device as recited in claim 16 , wherein the third access command is selected by generating a seek profile for the first actuator based on To 2 .
22. The data storage device as recited in claim 16 , further comprising a means for concurrently seeking the first actuator and the second actuator during at least part of To 2 .