Alan Watson wrote:
>
> I've had two disconcerting experiences lately. Last month,
> we upgraded a Sun from Solaris 2.6 to Solaris 2.7; it got
> faster. Last week, I upgraded my dual 450 MHz PII machine
> from RedHat 5.2 (2.0.36) to RedHat 6.0 (2.2.5-15smp); it got
> slower.
>
> I'm working on a two-stage image compression method. The
> image is quantized in one process and fed into gzip or bzip2
> using popen(). In sh terms, this is "process1 | process2".
> This used to parallelize quite nicely, with one process
> running on each processor, but now about the best I can get
> is 120% CPU usage, often less. Overall, the pipe is slower.
>
Please attached find the following:
1) rpm of nbench which contains nbench (several binaries compiled with
different compilers and optimization flags are available for
comparison).
2) HTML documnet summaruzing the results
3) text version of the same document.
The short version is:
For egcs compiler, you need to compile with -mpentiumpro switch on
Pentium II machines. Binaries compiled with -m386 or -m486 switch will
run slower than binaries compiled with gcc!
I have tried to post it on slashdot twice, but was not able to get
through.
Please check it and spread the word, I think this is important.
And no, the issue is not kernel related.
--
----------------------------------------
Constantine Gavrilov
Unix System Administrator and Programmer
Orbotech
Yavne 81102, Israel
Phone: (972-8)-942-3064
Fax: (972-8)-942-3800
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