Re: Ide performance (was RAID0 Performance problems)

Re: Ide performance (was RAID0 Performance problems)

[Philippe Amelant]

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 *** ujq7@rz.uni-karlsruhe.de
> 
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Re: Ide performance (was RAID0 Performance problems)

[Phil]

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.

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

Re: Ide performance (was RAID0 Performance problems)

[Jakob Østergaard]

On Tue, Apr 17, 2001 at 11:50:27PM +0200, Phil wrote:
> 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.
> 
> Hi
> 
> I have the same problem, but i think it 's a BX chipset related problem.

I have two SMP machines running RAID-0 on a BX chipset, without any
performance problems (~30-40 MB/sec on two disks, ~90MB/sec on five)

Kernel 2.4.3

> 
> I Have a BP6 whit a BX chipset and a htp 366 chipset.
> on a single device, hdparm report ~ 18/19 MB/s

Mine are Asus P2B-D boards

-- 
................................................................
:   jakob@unthought.net   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:

Ide performance (was RAID0 Performance problems)

[Andreas Peter]

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 *** ujq7@rz.uni-karlsruhe.de