Re: Benchmark (Phoronix): FreeBSD 9.0-RC2 vs. Oracle Linux 6.1 Server

On Wed, Dec 21, 2011 at 1:16 PM, Randy Schultz <[email protected]> wrote:
> On Tue, 20 Dec 2011, Matthew Tippett spaketh thusly:
>
> -}There are still possible issues with those benchmarks.  The Xeon has known
> -}problems scaling from 6 to 12 cores (well enabling the hyperthreading), so you
> -}may find that some platforms are penalized in performance if HT is turned on.
> -}See the scaling that Phoronix has done in
> -}
> -}http://openbenchmarking.org/result/1112166-AR-1112153AR03
> -}
> -}Most systems are good with scaling on real cores, the hyperthreading (and for
> -}that matter the Bulldozer thread affinity) can really break performance.
> -}Different platforms have different behaviours.  Benchmarking is a mucky
> -}business..
>
> This brings up a good point.  While I don't have any hard #'s, I suspect the
> vast majority of SA's do not have/spend much time tweaking this and tuning that.
> Order the box, drop the OS on it, install needed bits and go.  Saying "oh for
> app X you need to tune these sysctl's", while it may be entirely true, kinda
> throws things out the window.  It seems that once one starts down that slippery
> slope, it merely becomes a game of how much time to you have to "tune 1 more
> thing".  ;>  I think Phoronix has the right idea of just grabbing a stock box
> and not looking into what needs to be tweaked for a specific app.
>

I think that a good SA will at least consider how drives are arranged.
We don't just slap ZFS on a single disk and expect magic to happen, we
consider how write heavy a system will be and consider a dedicated
ZIL, we consider what proportion of files will be re-read and how much
application memory will be required and adjust ARC and L2ARC
accordingly. Tuning and foresight are important.

Cheers

Tom
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-performance
To unsubscribe, send any mail to "[email protected]"