RE: [GENERAL] Performance

Jackson, DeJuan <djackson@cpsgroup.com>

From: "Jackson, DeJuan" <djackson@cpsgroup.com>
To: Statistical Solutions <statsol@statsol.com>, pgsql-general@postgreSQL.org
Date: 1999-03-30T17:26:55Z
Lists: pgsql-general
Don't forget about IO speeds as well.
	-DEJ

> [snip]
> > Using the rc5 client as a 'benchmark' (what else has 
> programmers working
> > hard to optimize their code to get the best numbers on 
> it?), we found that
> > when comparing a Dual-PII 450 against an Sparc E450/400Mhz, 
> the E450 came
> > in at ~30% less powerful then the Dual-PII ...
> > 
> > If you take a look at 
> http://infopad.EECS.Berkeley.EDU/CIC/summary/local,
> > it shows comparisons of the various CPUs out there, up 
> until Nov/98 ...
> > the Intel CPUs blow away the Sparc chip's in integer 
> arithmetic, while the
> > Sparc excels in floating point.  Your operating system, and 
> the database,
> > tends to do most stuff in integer, so you get performance boons that
> > way...
> > 
> > The other thing to consider is that you are comparing two 
> differences, not
> > just one.  Different CPUs and different operating systems.  
> Solaris isn't
> > nicknamed 'slowaris' for nothing :)  Its a bloated OS, 
> albeit stable...
> > 
> 
> The original poster noted using Solaris 2.5.1 -- been there, 
> done that, it
> certainly can be slow.  A long time ago, I contacted Sun 
> about this.  They
> acknowledged a problem with the dynamic library loading 
> routines.  I have
> a Dual Sparc 125/512 running Solaris 2.6 and a dual 
> pentium-100 running
> 2.5.1.  I'll test some to see if this might be 2.5 v. 2.6 OS 
> differences,
> although there is stil the underlying hardware issue.
> 
> The second point however, is clock speeds.  Two 167 CPUs <> 
> One 333 CPU.
> 
> The third is the SPARC chip's cache versus the Intel chip's 
> cache.  I know
> SUN and Ross were making chips with as little as 128 cache, 
> and the SPEC
> marks for the 128 v. 256 v 512 v 1024 cache are phenomenal.  
> So just out
> of curiousity, what's the cache size on the SPARC and Intel chips
> respectively?
> 
> > On Tue, 30 Mar 1999, Jason wrote:
> > 
> > > Looking for a little reasoning behind our performance 
> difference on 2
> > > different platforms.  We have been running postgres on 
> our sparcs, and
> > > have come to rely on the dB quite heavily.  We have 
> dedicated a box to
> > > doing nothing but our postgres work.  Here is what we have:
> > > 
> > > Dual Sparc 167
> > > 512 MB RAM
> > > Solaris 2.5.1
> > > 
> > > Performance seemed reasonable to us, until we ran the 
> same database and
> > > queries on the following machine:
> > > 
> > > Intel Celeron 333
> > > 128 MB RAM
> > > Red Hat Linux 5.2
> > > 
> > > We have a passwd style database with 65,000 rows.  We 
> updated 20,000 of
> > > them with a SQL update command, setting a single integer 
> field to a
> > > value.  Both boxes where indexed the same, and had 
> identical data.  The
> > > Sparc took near 10 minutes to complete, while the Intel took ~30
> > > seconds.  This is just one case, but many very similar 
> tests had the
> > > same results.
> > > 
> > > Now I love Linux, and the price compared to a Sparc makes it much
> > > simpler to get one on line.  However, I can't understand 
> why the Sparc
> > > would lag so far behind.  We are starting Postgres the 
> same on both
> > > machines:
> > > 
> > > su - postgres -c "/usr/local/pgsql/bin/postmaster -B 256 
> -o -F -i -S"
> > > 
> > > We are looking at getting a dual 400 Intel Pentium II box 
> with Red Hat
> > > to migrate all of the Postgres work to.  But in the 
> meantime, is there a
> > > way to optimize the performance on the Sparc?  Thanks in advance.
> > > 
> > > -Jason Neumeier.
> > > 
> > > 
> > > 
> > 
> > Marc G. Fournier                   ICQ#7615664              
>  IRC Nick: Scrappy
> > Systems Administrator @ hub.org 
> > primary: scrappy@hub.org           secondary: 
> scrappy@{freebsd|postgresql}.org 
> > 
> > 
> > 
> 
>