Re: Some NCQ numbers...

[Bill Davidsen <davidsen@tmr.com>]

Justin Piszcz wrote:
> 
> 
> On Wed, 4 Jul 2007, Justin Piszcz wrote:
> 
>> On Wed, 4 Jul 2007, Michael Tokarev wrote:
>>
>> > Tejun Heo wrote:
>> >> 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.
>> >
>> > Here are actual results - the tests were still running when
>> > I replied yesterday.
>> >
>> > Again, this is Seagate ST3250620AS "desktop" drive, 7200RPM,
>> > 16Mb cache, 250Gb capacity.  The tests were performed with
>> > queue depth = 64 (on mptsas), drive write cache is turned
>> > off.
>>
>> I found AS scheduler to be the premium and best for single-user 
>> performance.
>>
>> You want speed? Use AS.
>>
>> http://home.comcast.net/~jpiszcz/sched/cfq_vs_as_vs_deadline_vs_noop.html
>>
>>
> 
> Does not include noop-- tested the main three though, renamed :)
> 
> http://home.comcast.net/~jpiszcz/sched/cfq_vs_as_vs_deadline.html
> 
> And for the archives:
> 
> p34-cfq,15696M,77114.3,99,311683,55.3333,184947,38.6667,79842.7,99,524065,41.3333,634.033,0.333333,16:100000:16/64,1043.33,8.33333,4419.33,11.6667,2942,17.3333,1178,10.3333,4192.67,12.3333,2619.33,19 
> 
> p34-as,15696M,76202.3,99,443103,85,189716,34.6667,79552,99,507271,39.6667,607.067,0,16:100000:16/64,1153,10,13434,36,2769.67,16.3333,1201.67,10.6667,3951.33,12,2665.67,19 
> 
> p34-deadline,15696M,76933.3,98.6667,386852,72,183016,29.6667,79530.7,99,512082,39.6667,678.567,0,16:100000:16/64,1230.33,10.3333,12349,32.3333,2945,17.3333,1258,11,8183,22.3333,2867,20.3333 
> 
I looked at these before, did you really run with a chunk size of just 
under 16GB, or does "15696M" have some inobvious meaning?

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot