[vdr] Re: Disk performance (was: vdr - some general questions)

[Stefan Lang <steven@organet.com>]

Am Freitag, 26. April 2002 15:34 schrieben Sie:
> hi list!
>
> how can i know if my system REALLY uses dma ??
> while booting i see the following:
>
> ALI15X3: chipset revision 193
> ALI15X3: not 100% native mode: will probe irqs later
>     ide0: BM-DMA at 0xa800-0xa807, BIOS settings: hda:DMA, hdb:pio
> ALI15X3: simplex device:  DMA disabled
> ide1: ALI15X3 Bus-Master DMA disabled (BIOS)
>
> when using hdparm /dev/hda it says:

hdparm -d1 /dev/hdx
switches basic dma usage on!

hdparm -X66 /dev/hdx 
controls the dma mode, here udma2! notice the upper case "X" not "x"
It is -X64 plus the wanted udma-mode (-X64+2 = -X66)

hope it helps!
>
> and hdparm -t /dev/hda gives me:
>
> Timing buffered disk reads:  64 MB in  6.02 seconds = 10.63 MB/sec
>
> i think this is not very good for a 80gig ide western digital disk.
> it is connected thru the "normal" 40pin ide cable, because my
> mabo is only capable of udma-2.
>
> ./bonnie++-1.02c/bonnie++ -u 500:100 -s 250 gives me:
>
> Version 1.02c       ------Sequential Output------ --Sequential
> Input- --Random-
>                     -Per Chr- --Block-- -Rewrite- -Per
> Chr- --Block-- --Seeks--
> Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec
> %CP
> vdr            250M  2691  83 12927  31  7604  30  3076  91 14596  36 112.4
> 1
>                     ------Sequential Create------ --------Random
> Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read---
> -Delet e--
>               files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec
> %CP
>                  16  1048  88 +++++ +++  1142  89   690  65 +++++ +++   455
> 39
>
> are the readings ok? what do you think?
>
> thanx,
>
> servus hannes!
>
> > Am Freitag, 26. April 2002 11:47 schrieb Tobias Meyer-Janson:
> > > > My System:
> > > > Duron 1GHz/256MB/80GB, [...]
> > > > Suse 7.3 Pro, only reiser FS, [...]
> > > > Elitegroup K7S5A Mainboard with on board
> > > >     "Dual PCI IDE interfaces - support four IDE devices
> > > >     (PIO mode 4, DMA Mode 2, Ultra DMA 33/66/100)"
> > > > 1st Controller: HD, 2nd: DVD-ROM,
> > > > [...]
> > > > I asked hdparm:
> > > >     I/O support =  0 (default 16-bit)
> > > >     using_dma   =  1 (on)
> > >
> > > The HD is a Maxtor 4D080H4 80 GB IDE. I know it's not the fastest but I
> > > thought some DVB-Streams would be no problem for any modern HD.
> > > How can I check if the HD is the problem? As I mentioned earlier I have
> > > also often digital artefacts both in picture and sound.
> > >
> > > Is it enough to switch DMA on (hdparm says it *is* on) or should I use
> > > a special DMA-Mode? I know different HDs and controller have different
> > > DMA features - is this configured automatically? I think default should
> > > be the fastest possible.
> >
> > I would _measure_ the disk performance with bonnie or bonnie++
> >
> >   http://www.coker.com.au/bonnie++/
> >
> > liquid:/video # bonnie++ -u 500:100 -s 250
> > Version  1.01    ------Sequential Output------ --Sequential
>
> Input- --Random-
>
> >                  -Per Chr- --Block-- -Rewrite- -Per
>
> Chr- --Block-- --Seeks--
>
> > Machine     Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec
>
> %CP
>
> > liquid      250M  8177  76 22123  34 11755  12  8923  85 26080  15 149.3
>
> 0
>
> >                  ------Sequential Create------ --------Random
>
> Create--------
>
> >                  -Create-- --Read--- -Delete-- -Create-- --Read---
> > -Delete