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Re: [vox-tech] Hard Disk Info
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Re: [vox-tech] Hard Disk Info



On Mon, Apr 15, 2002 at 11:20:00AM -0700, Peter Jay Salzman wrote:
> the important consequence is that there's no way
> (that i know of) to differentiate between a UDMA 66 and UDMA 100 drive.
> i've been trying to figure out this one for awhile now.

  If I'm not mistaken you can tell what type UDMA drive you have...

in the output of "-i" it tells you which dma modes the drive supports 
  sdma - is ancient and 'single word' dma
  mdma - is old 'multi-word' dma peaks out about 16 MiB/s
  udma - is modern 'ultra' dma peaks out about 133 MiB/s


http://www.pcguide.com/ref/hdd/if/ide/modesUDMA-c.html
# This table shows all of the current Ultra DMA modes, along with
# their cycle times and maximum transfer rates:
#
# ====================================================================
# = Ultra DMA =  Cycle Time   = Maximum Transfer = Defining Standard =
# =   Mode    = (nanoseconds) =   Rate (MB/s)    =                   =
# ====================================================================
# =  Mode 0   =      240      =       16.7       =    ATA/ATAPI-4    =
# ====================================================================
# =  Mode 1   =      160      =       25.0       =    ATA/ATAPI-4    =
# ====================================================================
# =  Mode 2   =      120      =       33.3       =    ATA/ATAPI-4    =
# ====================================================================
# =  Mode 3   =      90       =       44.4       =    ATA/ATAPI-5    =
# ====================================================================
# =  Mode 4   =      60       =       66.7       =    ATA/ATAPI-5    =
# ====================================================================
# =  Mode 5   =      40       =      100.0       =   ATA/ATAPI-6?    =
# ====================================================================

  hdparm will tell you which mode the drive is currently using...
the little stars indicate what the drive is working with right now.
hdparm can be used to switch the mode to something else, with the
-X option.


/dev/hda:
 Model=Maxtor 71626 AP, FwRev=QA3C1D20, SerialNo=V600K8CS
[...]
 DMA modes: sdma0 sdma1 *sdma2 mdma0 mdma1 *mdma2

/dev/hdc:

 Model=WDC AC420400D, FwRev=J58OA30K, SerialNo=WD-WT6620029337
[...]
 DMA modes: mdma0 mdma1 *mdma2 udma0 udma1 udma2 udma3 udma4
 Drive Supports : ATA/ATAPI-4 T13 1153D revision 17 : ATA-1 ATA-2 ATA-3 ATA-4

/dev/hdd is now offline but I think it supports udma5...

> begin Stephen M. Helms <Mytho_X@pacbell.net> 
> > I missed in my last post that you tried the -I option.  Rod is correct 
> > that the -t option will report the read speed of the drive.  This will 
> > not tell you the speed the actual disk is capable of.  You can 
> > experiment with hdparm to fine tune the speed.
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