[lug] hdparm and udma

[Ben]

I just bought a new hard drive (EIDE) and installed it as the secondary
master. I compared original EIDE hard drive with 'hdparm -t /dev/hd[ac]'
and both got ~60MB/s. Great. Then when I copied my data between the
drives, I switched the new hard drive to be my primary (master), and the
old to be my secondary (master). I then ran the same speed test on both
drives, and my old drive (now hdc) is getting 30MB/s. The commands are
shown below, but when I run hdparm -i /dev/hdc it is set to udma2 mode,
but supports up to udma6. When I set it to udma5 or 6 (hdparm -X udma6)
it says it has set the drive to udma5, but hdparm -i shows that nothing
has changed (udma2). Now my hda drive is using udma5, so my kernel and
motherboard support the higher speed. And since I was getting 60MB/s on
both drives I don't think it is primary vs secondary issue, but I don't
know. Any ideas? 

Thanks,

Ben



hdparm -i /dev/hdc

Model=Maxtor 6Y080P0, FwRev=YAR41BW0, SerialNo=Y26FDN2E
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=7936kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=160086528
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: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-7 T13 1532D revision 0:  ATA/ATAPI-1
ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7
* signifies the current active mode



hdparm -i /dev/hda

Model=WDC WD1600JB-00REA0, FwRev=20.00K20, SerialNo=WD-WCANM5408681
Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs
FmtGapReq }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=50
BuffType=unknown, BuffSize=8192kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes:  pio0 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 ATA/ATAPI-2 ATA/ATAPI-3
ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7
* signifies the current active mode