Checking the DMA/UDMA modes for SATA drive

kushalkoolwal · 10-05-2007, 01:07 PM

Hi,

I have a VIA CX700 M2 machine with a SATA drive configured as Primary Master. I am using 2.6.21.7 Kernel on Debian etch and I would like to know whether my SATA drive is using DMA Mode or not? What should I see in the "dmesg" output that will tell me if my SATA drive is using DMA/UDMA mode or not?

Should SATA drive appear as /dev/sdx or /dev/hdx?

My guess is that my drive is in PIO mode.

makuyl · 10-05-2007, 01:59 PM

Post the output of "dmesg|grep DMA". It should include "Using ?DMA mode" etc.
I suppose you have activated DMA for the drive in your BIOS.
I don't use a debian kernel, but 2.6 kernels should set it as sd?.

HappyTux · 10-05-2007, 03:54 PM

There is no such thing as a Master mode setting for SATA it is the only device on its bus therefore it is a Mater by default. If you are concerned about the speed of your drive use the hdparm program as root with something like hdparm -Tt /dev/sda then check the second speed it should be somewhere above 40-45MB/sec to anywhere up to 60-70. As to how the hard drive appears it can be either sd or hd depending on whether you have enabled the IDE emulation in your BIOS.

Code:

HappyTux:/home/stephen# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   3140 MB in  2.00 seconds = 1570.60 MB/sec
 Timing buffered disk reads:  164 MB in  3.01 seconds =  54.46 MB/sec

HappyTux:/home/stephen# hdparm -i /dev/sda

/dev/sda:

 Model=ST3400832AS                             , FwRev=3.03    , SerialNo=            3NF0XAJV
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=8192kB, MaxMultSect=16, MultSect=?16?
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
 IORDY=on/off, tPIO={min:240,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
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: Unspecified:  ATA/ATAPI-1,2,3,4,5,6,7

 * signifies the current active mode

HappyTux:/home/stephen# hdparm  /dev/sda

/dev/sda:
 IO_support    =  0 (default 16-bit)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 48641/255/63, sectors = 781422768, start = 0