Charles Plessy wrote:
Le Tue, Aug 05, 2008 at 04:26:27PM +0200, Michel Dänzer a écrit :
On Tue, 2008-08-05 at 23:17 +0900, Charles Plessy wrote:
Another example I have is a map website by Yahoo Japan:
http://map.yahoo.co.jp/pl?type=scroll&lat=35.35961995&lon=138.73361576&sc=7&mode=map&pointer=on
With Iceweasel it is slow on G5 and fluid on Intel.
With the same graphics card and drivers?
Good point.
A last example to explain the feeling of slowness: aptitude. To avoid
differences in package lists, I ran `aptitude full-update' in an up to
date sid cowbuilder (yes, there can be smarter system for benchmark, but
on the other hands we can expect some kind of standardness). On a dual
2GHz G5, the command takes around 4.1 seconds to complete. On a Core2Duo
2 GHz (amd64), it takes around 1.5 seconds.
If you want to factorize out pure cpu/memory performance versus video
performance, you'd have to make sure the commands you're trying don't
trigger any screen output.
Run something like:
LOGFILE=`tempfile`; time $your_command > "$LOGFILE" 2>&1
(Or, to make sure there's no difference if one of your systems have /tmp
on tmpfs and the other doesn't, run
time $your_command > /dev/null 2>&1
)
With my lack of technical knowledge, I am obviously going nowhere. But I
hope that I can trigger the curiosity of somebody who would eventually
find "someting missing" in the default config of powerpc machines…
Have a nice day,
Some ideas:
- check whether cpu frequency scaling works, i.e. you're not always
running on a lower than maximal cpu frequency. (How?: this works on my
x86_64 machine:
$ grep -i mhz /proc/cpuinfo
Or, better:
$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
(as root):
# cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq
and to set it manually to "performance" mode:
# for f in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
echo performance > "$f"; done
)
- a simple cpu benchmark I'm often using for quick checks is:
(this is on a Core 2 duo at 2.5 Ghz, with perl 5.10.0-11.1 from lenny)
[EMAIL PROTECTED]:~$ time perl -we 'for(1..10000000) { $z++ } print "$z\n"'
10000000
real 0m0.607s
user 0m0.604s
sys 0m0.004s
[EMAIL PROTECTED]:~$ time perl -we 'defined(fork) or die; for(1..10000000) {
$z++ } print "$z\n"; wait'
10000000
10000000
real 0m0.766s
user 0m0.768s
sys 0m0.000s
[EMAIL PROTECTED]:~$ time perl -we 'defined(fork) or die; defined(fork) or die;
for(1..10000000) { $z++ } print "$z\n"; wait; wait'
10000000
10000000
10000000
10000000
real 0m1.286s
user 0m2.536s
sys 0m0.000s
Obviously this is also a little dependent on the Perl version but that
factor shouldn't make more than maybe 10% of a difference. And Perl
*might* also be tuned better for x86{,_64} than ppc, of course -- but on
G3 machines this gave very comparable numbers for me (I did not see much
of an advantage for the x86 architecture).
Also make sure your system isn't running any background jobs, of course;
check with top. BTW if you press "1" in top you'll see the load on each
cpu separately.
Christian.
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