Hi
I have the same problem, but i think it 's a BX chipset related problem.
I Have a BP6 whit a BX chipset and a htp 366 chipset.
on a single device, hdparm report ~ 18/19 MB/s
with 2 devices on the same chipset (hda/hdc)
hdparm report ~ 9 MB/s each
with 2 devices not on the same chipset (hda/hdg)
hdparm report ~ 16/17 MB/s
Le 15 Apr 2001 21:08:04 +0200, Andreas Peter a écrit :
> Hi,
> I've posted about performance problems with my RAID0 setup.
> RAID works fine, but it's too slow.
> But now it seems not to be a problem with the md code, it's an ide problem.
> There are two HDs in my PC: /dev/hda and /dev/hdc. No other devices are
> attached to the ide-bus.
> PC is a SMP-System, 2 Celeron 533, Gigabyte 6BXDS with Intel BX-Chipset,
> 66MHz FSB.
> The hdparm settings:
>
> bash-2.04# hdparm /dev/hda /dev/hdc
>
> /dev/hda:
> multcount = 0 (off)
> I/O support = 3 (32-bit w/sync)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> nowerr = 0 (off)
> readonly = 0 (off)
> readahead = 0 (off)
> geometry = 59556/16/63, sectors = 60032448, start = 0
>
> /dev/hdc:
> multcount = 0 (off)
> I/O support = 3 (32-bit w/sync)
> unmaskirq = 1 (on)
> using_dma = 1 (on)
> keepsettings = 0 (off)
> nowerr = 0 (off)
> readonly = 0 (off)
> readahead = 0 (off)
> geometry = 59556/16/63, sectors = 60032448, start = 0
>
> I've tested a lot of variations of this settings (multcount=16,
> unmaskirq=0...) without succes.
> The performance of the RAID doesn't increase :-(
> hdparm -tT on a single HD (dev/hda3 is the RAID-partition) reports a very
> good performance:
>
> bash-2.04# hdparm -tT /dev/hda3
>
> /dev/hda3:
> Timing buffer-cache reads: 128 MB in 1.42 seconds = 90.14 MB/sec
> Timing buffered disk reads: 64 MB in 2.27 seconds = 28.19 MB/sec
>
> But if I start 2 hdparms simultanous (one on /dev/hda3 the other on
> /dev/hdc3) the performance on the HDs decreases to 1/2 of the original speed:
>
> bash-2.04# hdparm -tT /dev/hda3
>
> /dev/hda3:
> Timing buffer-cache reads: 128 MB in 2.27 seconds = 56.39 MB/sec
> Timing buffered disk reads: 64 MB in 4.56 seconds = 14.04 MB/sec
>
> bash-2.04# hdparm -tT /dev/hdc3
>
> /dev/hdc3:
> Timing buffer-cache reads: 128 MB in 2.25 seconds = 56.89 MB/sec
> Timing buffered disk reads: 64 MB in 4.49 seconds = 14.25 MB/sec
>
> The performance of the RAID0:
>
> bash-2.04# hdparm -tT /dev/md0
>
> /dev/md0:
> Timing buffer-cache reads: 128 MB in 1.35 seconds = 94.81 MB/sec
> Timing buffered disk reads: 64 MB in 3.11 seconds = 20.58 MB/sec
>
> Tests with bonnie or iozone have the same reuslts, RAID is slower then a
> single HD :-(
>
> Does anybody has an idea what's wrong with my setup??
>
> Thx,
> Andreas
> --
> Andreas Peter *** [EMAIL PROTECTED]
>
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