Understanding the time command

Luis Paulo luis.barbas at gmail.com
Sat Aug 14 16:37:47 UTC 2010

On Thu, Aug 12, 2010 at 12:24 PM, Gary Jarrel <garyjarrel at gmail.com> wrote:
> Hi All
> I found that one of my systems runs a bit sluggish, and interestingly
> enough it's the one with the fastest processor and most memory. My
> feeling is that the problem is somewhere in HDD access (IO problem of
> some sort) So before I spend countless hours on finding where the
> problem is I though I'd do one quick test as follows:
> time tar xvf file.tgz
> file.tgz is 600Mb in size and my results:
> System A (sluggish feeling)
> real    0m13.268s
> user    0m3.890s
> sys     0m13.090s
> System B
> real    0m12.918s
> user    0m3.300s
> sys     0m0.990s
> Now I am trying to understand why the huge difference in sys time but
> not in the others.
> Some specs of the systems: System A - Core i7, 12GB RAM. System B -
> Core i5 8GB RAM!
> The main difference is System B runs an Adaptec RAID Controller with 2
> Seagate SATAII Enterprise drives while System A has a Samsung 750GB
> SATAII drive connected to the SATA controller of an MSI Motherboard!
> Any ideas would be welcome, as I really want to get this system up to
> scratch since it's my development machine.
> Cheers,
> Gary

So the sys difference can have something to do with system A having a
true raid controler and B a fakeraid? Just what occurd to me.

Of course I don't even know if that's a true premisse.

Also, I don't understand why does it feel "sluggish" if the real time
is the same. I guess you mean that you were expecting system A to be
much faster, no? Or do you feel that system A is really slower in the
overall or in same tasks?

Hope you solve it :) Regards

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