SSD power management with hybrid PCIe link state method
Instead of the Peripheral Component Interconnect (PCI) Express (PCIe) link speed modulation and the PCIe link power state being utilized separately, the PCIe link speed modulation and PCIe link power state strategies are used in combination. The combination balances between the PCIe front end energy cost, the backend energy cost, and the quality of service (QOS). The performance/power space of the solid state drive (SSD) is mapped to the PCIe link speed modulation and PCIe link power state strategies to configure four distinctive zones, which provide high QoS at high performance points with a graceful performance degradation towards the lower performance points. A power/thermal constrained system dictates a certain performance that the SSD will be able to satisfy optimally by using both methods at different performance points.
1 . A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
modulate link speed between the data storage device and a host device;
alternate power state duty cycle between an active state and an idle state; and
adjusting the modulating and the alternating to achieve a predetermined energy usage and quality of service (QoS), wherein the modulating and alternating occur in parallel.
2 . The data storage device of claim 1 , wherein the controller comprises a link speed inference engine.
3 . The data storage device of claim 2 , wherein the controller further comprises an energy management duty cycle driver.
4 . The data storage device of claim 1 , wherein the controller is configured to increase or decrease the link speed.
5 . The data storage device of claim 4 , wherein the increase or decrease is in response to changing data storage device conditions.
6 . The data storage device of claim 5 , wherein the controller is configured to maintain the predetermined energy usage based upon the adjusting.
7 . The data storage device of claim 5 , wherein the controller is configured to maintain the QoS based upon the adjusting.
8 . The data storage device of claim 1 , wherein the controller is configured to receive an indication of a predetermined amount of power that can be consumed.
9 . The data storage device of claim 1 , wherein the adjusting is in response to thermal measurements.
10 . A data storage device, comprising
means to store data; and
a controller coupled to the means to store data, wherein the controller is configured to:
allocate energy budget for elements of the data storage device;
receive host device set parameters;
receive and store data internal parameters;
detect changes in operating conditions;
vary link speed based upon the host device set parameters and the stored data internal parameters; and
vary power state based upon the host device set parameters and the stored data internal parameters.
11 . The data storage device of claim 10 , wherein the controller is configured to convert a power limitation received from a host device to an energy number.
12 . The data storage device of claim 11 , wherein the controller is configured to calculate an amount of energy that can be used in a specific window of time.