Re: ThinkPad A31 Too Slow
On Sun, 13 Apr 2003, Aryan Ameri wrote:
> A couple of months ago I bought a ThinkPad A 31, it's one of IBM's
> high end models, with a 1.8 Ghz Pentium4 M, and 256 MB of DDR RAM.
> However I am not quite happy with the performance that I am getting
> out of this system.
Welcome to the Pentium-4, SpeedStep and slow, slow hard drives. :)
> The system's performance can't even compete with my desktop system,
> which is a Pentium III 600 Mhz with 128 MB SDRAM. This is my first
> notebook computer, before this I never owned a notebook, so I don't
> know, weather it is common for laptops to be so slow or not.
Sure. The most likely problems are:
1. SpeedStep has your CPU running at 1.2GHz, not 1.8.
To fix this, get a recent kernel with cpufreq support, enable SpeedStep
as the driver and have something frob the public interface (/proc in
2.4, /sys in recent 2.5) to get 'performance' mode.
You should be able to check this with the content of /proc/cpuinfo; mine
shows the two speeds correctly (1.2 vs 1.7) of my A31p.
2. The Pentium-4 itself.
The P4, even with the vastly improved core and cache in recent models,
is a bit of a mixed bag when it comes to performance. This is compounded
by the relative difference between RAM speed and the small cache on the
mobile P4.
So, in my experience, a 1.4GHz P3 will out-perform my 1.7 P4 running
Emacs Lisp stuff and feel a bit snappier when doing desktop stuff. It's
not much slower, in any sort of benchmark, just in "feel", though.
OTOH, my P4 performs almost 40% better than the P3 doing MPEG-2 video
encoding and runs modern 3d games a bit better under Windows than a P3
does...
Sadly, you can only get used to these oddities of performance. Well,
that, or you can sell the machine and get a P3 or Athlon based laptop
instead. ;)
3. The slow, slow laptop hard drive.
You got a good hard drive with your IBM laptop. It spins at 5400RPM, not
4200, and has a pretty low seek time all things considered. This is a
fine and happy thing, but it's almost 30% slower than a slow desktop
hard drive.
Depending on your kernel, this can hurt quite a bit, because seek time
always dominates performance and, sadly, 2.4 is pretty bad at handling
disk access.
2.5.66+ are better, a bit, and 2.5.75+ (or so, depending on when they
release the disk schedulers and the newer kernels) should improve things
further.
Overall, though, if it's doing a lot of disk stuff expect to wait and
wait...
You can't do much about this, either, unless you add a second hard drive
to the second ultra-bay slot and run a software RAID on it.
I am, for what it's worth, considering doing exactly this on my
system...
> I have never used any other OS on my laptop, other than Debian, so I
> don't know how the performance would be, using other distros, or other
> OSes. However it seems strange to me, that my laptop system is so
> slow.
Windows is probably going to feel a bit more snappy, mostly because of
the implementation of it's UI code. Other Linux based distributions are
going to make very little difference.
> I have heard that Debian's default installation, is a safe one, which
> doesn't take advantage of many of the system's bells and whistles. I
> wonder, are there any things that I can do to somehow tweak my system,
> and make it faster?
The biggest thing that improves performance for a P4 is getting a recent
2.5 kernel (at your own risk, of course), building that, then rebuilding
glibc to take advantage of the recent sysenter support. That's worth
around 30% less overhead on any syscall.
Other than that, not much is going to
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