Re: How to improve db performance with $7K?

To be honest, I've yet to run across a SCSI configuration that can
touch the 3ware SATA controllers. I have yet to see one top 80MB/sec,
let alone 180MB/sec read or write, which is why we moved _away_ from
SCSI. I've seen Compaq, Dell and LSI controllers all do pathetically
badly on RAID 1, RAID 5 and RAID 10.

35MB/sec for a three drive RAID 0 is not bad, it's appalling. The
hardware manufacturer should be publicly embarassed for this kind of
speed. A single U320 10k drive can do close to 70MB/sec sustained.

If someone can offer benchmarks to the contrary (particularly in
linux), I would be greatly interested.

Alex Turner
netEconomist

On Mar 29, 2005 8:17 AM, Dave Cramer <pg(at)fastcrypt(dot)com> wrote:
> Yeah, 35Mb per sec is slow for a raid controller, the 3ware mirrored is
> about 50Mb/sec, and striped is about 100
>
> Dave
>
> PFC wrote:
>
> >
> >> With hardware tuning, I am sure we can do better than 35Mb per sec. Also
> >
> >
> > WTF ?
> >
> > My Laptop does 19 MB/s (reading <10 KB files, reiser4) !
> >
> > A recent desktop 7200rpm IDE drive
> > # hdparm -t /dev/hdc1
> > /dev/hdc1:
> > Timing buffered disk reads: 148 MB in 3.02 seconds = 49.01 MB/sec
> >
> > # ll "DragonBall 001.avi"
> > -r--r--r-- 1 peufeu users 218M mar 9 20:07 DragonBall
> > 001.avi
> >
> > # time cat "DragonBall 001.avi" >/dev/null
> > real 0m4.162s
> > user 0m0.020s
> > sys 0m0.510s
> >
> > (the file was not in the cache)
> > => about 52 MB/s (reiser3.6)
> >
> > So, you have a problem with your hardware...
> >
> > ---------------------------(end of broadcast)---------------------------
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> >
> >
>
> --
> Dave Cramer
> http://www.postgresintl.com
> 519 939 0336
> ICQ#14675561
>
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