Re: [gentoo-user] Re: Normal disk speed?

[Daniel Troeder]

On 10/06/2010 10:04 AM, Adam Carter wrote:
> FYI some braindead benchmarking, reiserfs vs ext4, kernel 2.6.35-gentoo-r8
>
> Copy same DVD image from internal reiserfs drive to freshly formatted
> external drive;
> reiserfs    1m37.530s
> ext4        3m15.074s
>
> Then image copy on that external drive;
> # time cp CentOS-5.3-x86_64-bin-DVD.iso CentOS-5.3-x86_64-bin-DVD.iso2
> # time cp CentOS-5.3-x86_64-bin-DVD.iso CentOS-5.3-x86_64-bin-DVD.iso3
> reiser        1m44.719s and 1m51.441s
> ext4        3m24.337s and 4m30.534s
>
> Not that is matters, but create filesystem on 2TB drive;
> reiserfs    1m17.373s
> ext4        6m3.421s
>
> Didnt see that coming, I guess i'll stick with reiser3....
WOW! Those differences are crazy!

Please - I know benchmarking takes a lot of time - but could you check
something: the behavior those fs have at what time they flush data from
cache to disk is very different. Have you made sure that you measured
the time it really needs? I mean the difference between:

$ sync; time cp source dest
and
$ sync; time (cp source dest; sync)

Only the last measures somewhat correctly.

I'm irritated, because ext4 is extends based, and should behave much
better with big files than reiser3... not only less fragmentation, but
should also be faster...

Bye,
Daniel

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