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Re: Problems setting DMA



Leonardo Dias wrote:

> Have any of you guys ever had a problem setting DMA to a PC?

Here's what I do on an IBM Deskstar 45GB
First some info:

# hdparm -i /dev/hdb

/dev/hdb:

 Model=IBM-DTLA-307045, FwRev=TX6DA50C, SerialNo=YM0YMF43821
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=40
 BuffType=3(DualPortCache), BuffSize=1916kB, MaxMultSect=16, MultSect=off
 DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=88265520
 tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2 
 IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4 
 UDMA modes: mode0 mode1 mode2 mode3 mode4 *mode5 

# hdparm -Tt /dev/hdb

/dev/hdb:
 Timing buffer-cache reads:   128 MB in  0.90 seconds =142.22 MB/sec
 Timing buffered disk reads:  64 MB in 16.04 seconds =  3.99 MB/sec

Now the changes:

# hdparm -c3 /dev/hdb

/dev/hdb:
 setting 32-bit I/O support flag to 3
 I/O support  =  3 (32-bit w/sync)

# hdparm -d1 /dev/hdb

/dev/hdb:
 setting using_dma to 1 (on)
 using_dma    =  1 (on)

# hdparm -Tt /dev/hdb

/dev/hdb:
 Timing buffer-cache reads:   128 MB in  0.93 seconds =137.63 MB/sec
 Timing buffered disk reads:  64 MB in  1.84 seconds = 34.78 MB/sec


Bonnie reports:

              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
IBM IDE  1000 12476 98.2 32631 19.6 13175 15.2 12646 92.7 31695  8.1 173.9  0.9

-- 
Peter Galbraith, research scientist          <GalbraithP@dfo-mpo.gc.ca>
Maurice Lamontagne Institute, Department of Fisheries and Oceans Canada
P.O. Box 1000, Mont-Joli Qc, G5H 3Z4 Canada. 418-775-0852 FAX: 775-0546
    6623'rd GNU/Linux user at the Counter - http://counter.li.org/ 



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