Re: Resolution to UDMA performance issues on 2.0.36

M.Brands (shrike@il.fontys.nl)
Thu, 17 Jun 1999 07:58:16 +0200


On Wed, Jun 16, 1999 at 01:46:29PM -0400, Victor Orlikowski allegedly wrote:
> Well unfortunately, nothing else accounts for my results....
> Before killing the client, 4.8 M/sec
> After killing, 9.8M/sec.
> Could your greater results stem from the fact that you have it RAIDed?

Not in my situation. The separate disks perform about the same if I
shoot down rc5des. Have a look.

Btw. What kind of motherboard/cpu are you using? I'm running a Abit BH6
(BX chipset) with a Celeron 300A overclocked to 450 MHz. I used one of
these disks in a system with a K6-200 and a VIA chipset (TX clone) once,
but the disk would only do about 9.5 MB/sec. I didn't have VIA Apollo
support in the kernel though. Oh, and I'm running 2.2.6 on my box.

Mathijs

-----8<----------------------8<---------------------8<--------------
[root@bucephalus /root]# hdparm -i /dev/hda

/dev/hda:

Model=Maxtor 90845D4, FwRev=GAS54112, SerialNo=A40E3XGC
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=29
BuffType=3(DualPortCache), BuffSize=256kB, MaxMultSect=16, MultSect=off
DblWordIO=no, maxPIO=2(fast), DMA=yes, maxDMA=2(fast)
CurCHS=1027/255/63, CurSects=16514064, LBA=yes
LBA CHS=513/510/63 Remapping, LBA=yes, LBAsects=16514064
tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2
IORDY=on/off, tPIO={min:120,w/IORDY:120}, PIO modes: mode3 mode4
UDMA modes: mode0 mode1 *mode2

[root@bucephalus /root]# ps auxp 366
USER PID %CPU %MEM SIZE RSS TTY STAT START TIME COMMAND
shrike 366 95.1 0.1 1568 240 ? R N 04:43 172:19 rc5/rc5des -quiet
[root@bucephalus /root]# uptime
7:45am up 3:01, 3 users, load average: 1.00, 1.00, 1.06
[root@bucephalus /root]# hdparm -tT /dev/hd[ac] /dev/md0

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.00 seconds =128.00 MB/sec
Timing buffered disk reads: 64 MB in 4.32 seconds =14.81 MB/sec

/dev/hdc:
Timing buffer-cache reads: 128 MB in 1.05 seconds =121.90 MB/sec
Timing buffered disk reads: 64 MB in 4.43 seconds =14.45 MB/sec

/dev/md0:
Timing buffer-cache reads: 128 MB in 1.03 seconds =124.27 MB/sec
Timing buffered disk reads: 64 MB in 3.03 seconds =21.12 MB/sec
[root@bucephalus /root]# killall rc5des
[root@bucephalus /root]# hdparm -tT /dev/hd[ac] /dev/md0

/dev/hda:
Timing buffer-cache reads: 128 MB in 1.03 seconds =124.27 MB/sec
Timing buffered disk reads: 64 MB in 4.37 seconds =14.65 MB/sec

/dev/hdc:
Timing buffer-cache reads: 128 MB in 1.02 seconds =125.49 MB/sec
Timing buffered disk reads: 64 MB in 4.44 seconds =14.41 MB/sec

/dev/md0:
Timing buffer-cache reads: 128 MB in 0.94 seconds =136.17 MB/sec
Timing buffered disk reads: 64 MB in 3.02 seconds =21.19 MB/sec

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