On Wed, 19 Mar 2003, Benjamin Vander Jagt wrote:
> I haven't done any hard benchmarking yet. Here's what I have now. I'm > in RH8.0 right now, and playing an MP3 in XMMS took 0.2% of my CPU with > the precompiled i386 installation and the MP3 plugin RPM from GURU > labs. Simply rebuilding everything with the --target=athlon (nothing > else), I play MP3s with 0% CPU utilization. I'd have to do some long > term statistical logging to give you firmer numbers. Now yer attempt at any sort of useful numeric benchmark is noble..but this is particularly not useful. Why, you may ask? Well.... 1) a change from 0.2% to 0% is a measure of infinite improvement...find a better way to get a measureable benchmark. And even so I'm not even sure what you are measuring with this. ps's man page remarks on %CPU with: "It is time used divided by the time the process has been running. It will not add up to 100% unless you are lucky" how is this a useful benchmark? Can't a number of other factors..like other running processes get in the way of this measurement? This only becomes significant with reasonable statistics, and careful attention to the other things in the system are doing. But I would find a better measurement than this. When the man page sez you cant expect to see the number add up to 100%, a change of 0.2% has got to be in the accepted noise of the system, and invalidates the measurement.... this is rule #3 of junk science. http://chronicle.com/free/v49/i21/21b02001.htm 2) Your using 3rd party rpms/srpms....GOD ONLY KNOWS what settings were used to compile that original binary rpm from GURU labs. There are several levels of optimization. Did the guru labs compile that binary with -mcpu=i686? which is different than specifying -march=i686. Did GURU use -O2? AFAIK, redhat compiles their binaries for x86 with -mcpu=i686 and -O2. Go back....recompile the srpm for i386 with the Red Hat's default optimization settings...then recompile with yer -march change. If yer going to pretend to make a benchmark...make sure you know what the original binary was compiled to use, before you pretend to make a comparison. > CPU optimizations can make a huge difference. Consider how MMX and > 3D-Now! greatly reduce the program size, (and therefore) memory > consumption, and processor usage. Look at all the things in that sentence you talk about..and the only thing you include is the dubious %CPU stat. Do it right...or don't do it. -jef"trained to assume data is wrong..because his data usually is"spaleta -- Phoebe-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/phoebe-list
