Selective enablement of operating modes or features via host transfer rate detection
Selective enablement of operating modes or features of a storage system via host transfer rate detection enables, in some situations, enhanced performance. For example, a Solid-State Disk (SSD) having a serial interface compatible with a particular serial interface standard selectively enables coalescing of status information for return to a host based on detecting a particular host transfer rate capability. Some hosts are not fully compliant with the particular standard, being unable to properly process the coalesced status information. The selective enablement disables status coalescing for a non-compliant host and enables status coalescing for at least some compliant hosts, without the SSD having prior knowledge of coupling to a noncompliant/compliant host. The SSD conservatively determines the host is non-compliant/compliant based on a negotiated speed of the serial interface, and selectively disables/enables status coalescing in response to the negotiated speed.
1. A system comprising:
a storage device configured to serially interface to a host; and
a storage controller configured to determine whether a negotiated data transfer rate of a serial interface between the storage device and the host is at or above a predetermined threshold, the storage controller selectively enabling at least one storage-interface operating mode or feature when the negotiated data transfer rate is at or above the predetermined threshold,
wherein the serial interface and the storage controller are comprised in one or more Solid State Disks (SSDs), Hard Disk Drives (HDDs), Compact Disk (CD) and/or Digital Versatile/Video Disk (DVD) drives, and tape drives, and
wherein the at least one operating mode or feature comprises coalescing of status information returned to the host via status combining across multiple host requests.
2. The system of claim 1 , wherein the storage controller selectively disables the at least one storage-interface operating mode or feature when the negotiated data transfer rate is less than the predetermined threshold.
3. The system of claim 1 , wherein a first version of a serial interface standard specifies operation at a maximum nominal serial data transfer rate that is at or above the predetermined threshold, the first version of the serial interface standard specifies the at least one storage-interface operating mode or feature, a second version of the serial interface standard specifies operation at a maximum nominal serial data transfer rate that is below the predetermined threshold, the serial interface is compatible with the first and the second versions of the serial interface standard, and the serial interface is not compatible with the second version of the serial interface standard when the at least one storage-interface operating mode or feature is enabled.
4. The system of claim 3 , wherein the first and the second versions of the serial interface standard correspond to respective versions of a Serial Advanced Technology Attachment (SATA) standard.
5. The system of claim 1 , wherein the serial interface is compatible with at least one version of a Serial Advanced Technology Attachment (SATA) standard and the predetermined threshold is 6 Gb.
6. The system of claim 1 , further comprising the host, and wherein the host is enabled to process the coalesced status information.
7. The system of claim 1 , wherein the serial interface and the storage controller are comprised in one or more Solid State Disks (SSDs), and the storage device comprises flash memory comprised in at least one of the SSDs.
8. A method comprising:
serially interfacing a host with storage; and
selectively controlling enablement of at least one storage-interface operating mode or feature, the selectively controlling enablement selectively enabling the at least one storage-interface operating mode or feature,
wherein the selectively controlling enablement is dependent at least in part on a negotiated data transfer rate of the serially interfacing,
wherein the selectively controlling enablement selectively enables the at least one storage-interface operating mode or feature when the negotiated data transfer rate is at or above a predetermined threshold, and
wherein the at least one storage-interface operating mode or feature comprises coalescing of status information be returned to the host via status combining across multiple host requests.
9. The method of claim 8 , wherein the selectively controlling enablement selectively disables the at least one storage-interface operating mode or feature when the negotiated data transfer rate is less than the predetermined threshold.
10. The method of claim 8 , wherein a first version of a serial interface standard specifies operation at a maximum nominal serial data transfer rate that is at or above the predetermined threshold, the first version of the serial interface standard specifies the at least one storage-interface operating mode or feature, a second version of the serial interface standard specifies operation at a maximum nominal serial data transfer rate that is below the predetermined threshold, the serially interfacing is compatible with the first and the second versions of the serial interface standard, and the serially interfacing is not compatible with the second version of the serial interface standard when the at least one storage-interface operating mode or feature is enabled.
11. The method of claim 10 , wherein the first and the second versions of the serial interface standard correspond to respective versions of a Serial Advanced Technology Attachment (SATA) standard.
12. The method of claim 8 , wherein the serially interfacing is compatible with at least one version of a Serial Advanced Technology Attachment (SATA) standard and the predetermined threshold is 6 Gb.
13. The method of claim 8 , further comprising the host processing the coalesced status information.
14. The method of claim 8 , wherein the serially interfacing and the selectively controlling enablement are implemented in one or more Solid State Disks (SSDs), Hard Disk Drives (HDDs), Compact Disk (CD) and/or Digital Versatile/Video Disk (DVD) drives, and tape drives.
15. The method of claim 8 , wherein the serially interfacing and the selectively controlling enablement are implemented in one or more Solid State Disks (SSDs), and the storage comprises flash memory comprised in at least one of the SSDs.
16. A method comprising:
negotiating, by a storage controller, a nominal data transfer rate of a serial interface coupling a computing host and a solid state disk;
determining, by the storage controller, whether the nominal data transfer rate is at or above a predetermined threshold; and
selectively enabling, by the storage controller, coalescing of status information that is to be returned to the computing host via status combining across multiple host requests when it is determined that the nominal data transfer rate is at or above the predetermined threshold.
17. The method of claim 16 , further comprising:
selectively disabling, by the storage controller, coalescing of status information that is to be returned to the computing host via status combining across multiple host requests when it is determined that the nominal data transfer rate is less than the predetermined threshold.
18. The method of claim 16 , wherein the solid state disk comprises the storage controller that performs the negotiating, determining, and enabling.
19. The method of claim 16 , wherein the predetermined threshold is 6Gb.