Harddisk without DMA ?

I found that my harddisk does not use DMA transfer :

# hdparm /dev/hda

/dev/hda:
multcount = 16 (on)
IO_support = 3 (32-bit w/sync)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 7297/255/63, sectors = 117231408, start = 0

And the speed is pathetic :

# hdparm -tT /dev/hda

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.15 seconds =111.30 MB/sec
Timing buffered disk reads: 64 MB in 10.97 seconds = 5.83 MB/sec

Only 5.80+ MB/sec ...

However, it support some DMA transfer modes :

# hdparm -i /dev/hda

/dev/hda:

Model=ST360021A, FwRev=7.73, SerialNo=3HV4ETBG
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=unknown, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=117231408
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: device does not report version: 1 2 3 4 5

But why I cant set to use DMA ?

# hdparm -d1 -X67 /dev/hda

/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
setting xfermode to 67 (UltraDMA mode3)
HDIO_DRIVE_CMD(setxfermode) failed: Input/output error
using_dma = 0 (off)

Is this hardware related ? Kernel ? or ...

Please help.

 

 

 

 

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