What is NCQ? According to Wikipedia, ``Native Command Queuing (NCQ) is an extension of the Serial ATA protocol allowing hard disk drives to internally optimize the order in which received read and write commands are executed. This can reduce the amount of unnecessary drive head movement, resulting in increased performance (and slightly decreased wear of the drive) for workloads where multiple simultaneous read/write requests are outstanding, most often occurring in server-type applications.''

Jaromir writes to tech-kern: ``I plan to merge the branch to HEAD very soon, likely over the weekend. Eventual further fixes will be done on HEAD already, including mvsata(4) restabilization, and potential switch of siisata(4) to support NCQ.

The plan is to get this pulled up to netbsd-8 branch soon also, so that it will be part of 8.0.

Status:

• ahci(4) fully working with NCQ (confirmed with qemu, and real hw)
• piixide(4) continues working (no NCQ support of course) (confirmed in qemu)
• siisata(4) continues working (without NCQ still) (confirmed with real hw)
• mvsata(4) not yet confirmed working after changes, mainly due the DMA not really working on Marvell 88SX6042 which I have available - I have same issue as kern/52126
• other ide/sata drivers received mechanical changes, should continue working as before''