Hello, Michael Tokarev wrote: > Well. It looks like the results does not depend on the > elevator. Originally I tried with deadline, and just > re-ran the test with noop (hence the long delay with > the answer) - changing linux elevator changes almost > nothing in the results - modulo some random "fluctuations". I see. Thanks for testing. > In any case, NCQ - at least in this drive - just does > not work. Linux with its I/O elevator may help to > speed things up a bit, but the disk does nothing in > this area. NCQ doesn't slow things down either - it > just does not work. > > The same's for ST3250620NS "enterprise" drives. > > By the way, Seagate announced Barracuda ES 2 series > (in range 500..1200Gb if memory serves) - maybe with > those, NCQ will work better? No one would know without testing. > Or maybe it's libata which does not implement NCQ > "properly"? (As I shown before, with almost all > ol'good SCSI drives TCQ helps alot - up to 2x the > difference and more - with multiple I/O threads) Well, what the driver does is minimal. It just passes through all the commands to the harddrive. After all, NCQ/TCQ gives the harddrive more responsibility regarding request scheduling. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
