Re: RAID 0 not as fast as expected

That's an all PCI-X box which makes sense. There are 6 SATA controllers
in that little beastie also. You can always count on Sun to provide
over engineered boxes.

> -----Original Message-----
> From: pgsql-performance-owner(at)postgresql(dot)org
> [mailto:pgsql-performance-owner(at)postgresql(dot)org] On Behalf Of
> Joshua D. Drake
> Sent: Friday, September 15, 2006 12:01 AM
> To: Luke Lonergan
> Cc: Craig A. James; pgsql-performance(at)postgresql(dot)org
> Subject: Re: [PERFORM] RAID 0 not as fast as expected
>
> Luke Lonergan wrote:
> > Josh,
> >
> > On 9/14/06 8:47 PM, "Joshua D. Drake" <jd(at)commandprompt(dot)com> wrote:
> >
> >>> I've obtained 1,950 MB/s using Linux software RAID on SATA drives.
> >> With what? :)
> >
> > Sun X4500 (aka Thumper) running stock RedHat 4.3 (actually
> CentOS 4.3)
> > with XFS and the linux md driver without lvm. Here is a
> summary of the results:
> >
>
>
> Good god!
>
> >
> > Read Test
> > RAID Level Max Readahead (KB) RAID Chunksize Max Readahead
> on Disks
> > (KB) Max Time (s) Read Bandwidth (MB/s) 0 65536 64 256 16.689
> > 1,917.43 0 4096 64 256 21.269 1,504.54 0 65536 256 256 17.967
> > 1,781.04 0 2816 256 256 18.835 1,698.96 0 65536 1024 256 18.538
> > 1,726.18 0 65536 64 512 18.295 1,749.11 0 65536 64 256 18.931
> > 1,690.35 0 65536 64 256 18.873 1,695.54 0 64768 64 256 18.545
> > 1,725.53 0 131172 64 256 18.548 1,725.25 0 131172 64
> 65536 19.046
> > 1,680.14 0 131172 64 524288 18.125 1,765.52 0 131172 64 1048576
> > 18.701 1,711.14
> > 5 2560 64 256 39.933 801.34
> > 5 16777216 64 256 37.76 847.46
> > 5 524288 64 256 53.497 598.16
> > 5 65536 32 256 38.472 831.77
> > 5 65536 32 256 38.004 842.02
> > 5 65536 32 256 37.884 844.68
> > 5 2560 16 256 41.39 773.13
> > 5 65536 16 256 48.902 654.37
> > 10 65536 64 256 83.256 384.36
> > 1+0 65536 64 256 19.394 1,649.99
> > 1+0 65536 64 256 19.047 1,680.05
> > 1+0 65536 64 256 19.195 1,667.10
> > 1+0 65536 64 256 18.806 1,701.58
> > 1+0 65536 64 256 18.848 1,697.79
> > 1+0 65536 64 256 18.371 1,741.88
> > 1+0 65536 64 256 21.446 1,492.12
> > 1+0 65536 64 256 20.254 1,579.93
> >
> >
>
>
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