IDE Controller Transfer Mode

[Vincent Trouilliez]

On Sat, 14 Feb 2009 00:39:06 -0500
Pete Holsberg <pjh42 at pobox.com> wrote:

> How can I tell whether my IDE controller channel is in DMA or PIO mode?

You can use hdparm to interrogate the drive that's on said IDE channel.
It will return some info about the drive, and show you among many ther
things, the available modes (PIO and DMA) and highlight the one
currently in use.

Say you want to check sda, issue:

sudo hdparm -i /dev/sda


On my drive it return this:

*********************
/dev/sda:

 Model=SAMSUNG HD502IJ                         , FwRev=1AA01110,
SerialNo=S13TJDWQ412337 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=34902, SectSize=554, ECCbytes=4
 BuffType=DualPortCache, BuffSize=16384kB, MaxMultSect=16, MultSect=?16?
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=976773168
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 
 AdvancedPM=yes: unknown setting WriteCache=enabled
 Drive conforms to: unknown:  ATA/ATAPI-3,4,5,6,7

 * signifies the current active mode
************************

... which indicates that it's currently using Ultra DMA 6

HTH

--
Vince