Re: 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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