(u)dma/hdparm question

From: Sven Holm (noemailforusenet_at_hotmail.com.invalid)
Date: 10/31/03 

Date: Fri, 31 Oct 2003 17:42:31 +0100

Hello,

I have a question about using hdparm to set dma/udma modes.

My system:
M7VKA, Biostar, VIA, kt133, 384 MB RAM

hdparm -i /dev/hda:

Model=SAMSUNG SV4084H, FwRev=PM100-11, SerialNo=0265J1FNA14178
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
 RawCHS=16383/16/63, TrkSize=34902, SectSize=554, ECCbytes=4
 BuffType=3(DualPortCache), BuffSize=426kB, MaxMultSect=16, MultSect=16
 DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=79730784
 tDMA={min:120,rec:120}, DMA modes: mword0 mword1 *mword2
 IORDY=yes, tPIO={min:120,w/IORDY:120}, PIO modes: mode3 mode4
 UDMA modes: mode0 mode1 mode2 mode3 mode4 mode5
 Drive Supports : ATA/ATAPI-4 T13 1153D revision 17 : ATA-1 ATA-2 ATA-3
ATA-4 ATA-5 ATA-6

This is what I get after setting: hdparm -d1 -X34 /dev/hda, so I am
using mword2 dma mode for the disk.

Before, I was using udma mode4, but my system suffered from random
freezing, which are gone now, hopefully (after reducing the transfer
mode)

My question:
Is it safe to use a "normal" dma mode (mword2, for instance) for a disk
that is udma capable and with a BIOS which is set for udma?

My BIOS does only offer udma or non-udma, but no setting for simple dma!

Some people told me that setting -X34 is dangerous, because the
controller is set for udma, while the disk is now set for dma!

I also read the big fat warnings in the hdparm man page.

Is it true that I should NOT set a multiword dma mode, but either use
udma or disable it altogether?

So far, my system runs o.k. with this dma setting (-X34) AND the BIOS
being set for UDMA (I also run windows on the same machine).

Hints? Warnings?
Please reply, thanks.

Sven

Relevant Pages

  • Re: Wozu noch DOS?
    ... entweder kein UDMA-Kontroller vorhanden oder der UDMA-Modus im BIOS ... denn bei mir war im Bios jeder meiner UDMA-MoBos ... Ne ich glaube das wenige DOS-Anwendungen UDMA benutzen ... DMA beherscht, aber wahrscheinlich MS-DOS nicht bleibend dazu verhilft. ...
    (de.comp.os.msdos)
  • Cant change HD from PIO to UDMA
    ... When checking the Primary and IDE channels I see that device 0 (which is my ... primary HD) is set to "DMA if available" yet the current mode is "PIO Mode". ... its manual it should use UDMA if available. ... HD vendor and they are reporting that both my HDs are in good working ...
    (microsoft.public.windowsxp.hardware)
  • Cant change HD from PIO to UDMA
    ... When checking the Primary and IDE channels I see that device 0 (which is my ... primary HD) is set to "DMA if available" yet the current mode is "PIO Mode". ... its manual it should use UDMA if available. ... HD vendor and they are reporting that both my HDs are in good working ...
    (microsoft.public.windowsxp.general)
  • Re: Starting with Linux
    ... I rather felt that the drives would support this DMA. ... I have looked, yet again, at the configuration of this DMA. ... When I got to this stage before, I did try switching it to ON. ... I tried the first version of UDMA. ...
    (alt.os.linux.suse)
  • Festplatte nur über PIO
    ... >DMA eingestellt) nur in PIO übertragen. ... Maxtor UDMA 166 die im BIOS als UDMA-6 angezeigt und in ... Win2000 SP4 nur als PIO angezeigt wird. ... auf dem unveränderen Rechner wird die Maxtor ...
    (microsoft.public.de.german.win2000.hardware)