[sclug] Where to start troubleshooting machine speed?

[alan pearson]

cat /proc/cpu    (I think, it might be
/proc/processor)
It should tell you the spped the CPU is running at.

--- Alex Butcher <lug at assursys.co.uk> wrote:

> On Mon, 5 Sep 2005, Darren Davison wrote:
> 
> > I've got a desktop box running Gentoo that I've
> had for a while and also
> > recently installed Gentoo on a laptop that I use
> for work.  For some while
> > I've been suspicious of the general speed of the
> desktop but put it down
> > mainly to the graphics chipset (Intel 855G) not
> being much cop.
> >
> > The laptop however uses the same graphics chipset
> and has the same drivers
> > installed as the desktop,
> 
> They're the same drivers, but are they the same
> versions? As you're using
> Gentoo, were all your packages compiled in the same
> order, using the same
> version of the compiler and with the same flags and
> features enabled (or,
> preferably, exactly the same binaries)?
> 
> If the answer to any of those questions is 'no' or
> 'don't know', you're not
> performing an apples-to-apples comparison. Getting
> the same binaries on both
> machines should be the first step in any
> investigations you make; probably
> the most convenient way for you to do this would be
> to use Knoppix (or some
> other bootable live CD) temporarily, but installing
> a binary distro (e.g.
> Fedora, CentOS, SuSE) with the same errata packages
> installed would also be
> acceptable.
> 
> > but X apps noticeably all run much faster on the
> laptop.  It has more
> > memory than the desktop (2G vs 768Mb) but a slower
> processor (1.6Ghz vs
> > 2.4Ghz).  Funnily enough though, it also seems
> significantly quicker
> > compiling software than the desktop box.
> 
> Things I would look at:
> 
> - Disc DMA, interrupt unmasking, 32-bit IO
> (significant for compilation,
> amongst other things, I find)
> 
> - Check physical configuration of desktop machine
> (e.g. cabling, jumpers)
> especially if a DIY box (though I've had problems
> with largeish PC vendors
> misconfiguring the machines they've sold)
> 
> - X configuration (for X application performance)
> 
> - Booting the laptop's kernel with mem=768M to make
> its configuration more
> closely match that of the desktop.
> 
> - Comparing CPUs; cache and frontside-bus speed for
> a start.
> 
> - Running CPU benchmarks to verify that the 2.4GHz
> machine has a
> better-performing CPU than the 1.6GHz machine
> (remember that a CPU with a
> better architecture running at a lower clock speed
> can outperform poorer
> architectures running at faster clock speeds!)
> 
> - Check heatsink/fan in desktop; remember that Intel
> CPUs slow down if they
> overheat as a first step in protecting themselves
> from damage.
> 
> > It's all subjective of course, I have no
> benchmarks to offer, but the
> > difference in general speed of operation is very,
> very noticeable.
> >
> > The desktop always seems to have plenty of RAM
> free and it's certainly not
> > doing any swapping.  Any hints on where I should
> look to start figuring this
> > speed differential out?  Could it all really be
> just due to the extra RAM in
> > the laptop?
> >
> > Regards,
> 
> HTH,
> Alex.
> -- 
> Alex Butcher      Brainbench MVP for Internet
> Security: www.brainbench.com
> Bristol, UK                      Need reliable and
> secure network systems?
> PGP/GnuPG ID:0x271fd950                        
> <http://www.assursys.com/>
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