poor measured performance on Linux vs Windows (bad Compiler choices/options)

Robert Somerville
Robert Somerville
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Topic 188607

on Linux my mflops seem to be half what the windows machines running on the same processor gets.

This is truly hard to believe.

Have you tried the Intel Linux Compilers & sse2 instruction options ???

Robert Somerville

merle van osdol
merle van osdol
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poor measured performance on Linux vs Windows (bad Compiler choi

A while back I used the intel c/c++ compiler for linux available on the net and
used a small floating point (amateurish) program of mine. The results were astonishing to me. The intel compiler was 13 times as fast as the gnu compiler
shipping with debian kernel 2.6.8. Do you know what compiler einstein is using?
Do you know if they would qualify for the "free" use of the intel compiler? I
was going to try and recompile some of my downloaded linux programs but am having trouble getting thru the maze of the details of "make".

merle

What is freedom of expression? Without the freedom to offend, it ceases to exist.

— Salman Rushdie

Jordan Wilberding
Jordan Wilberding
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If you used the optimized

If you used the optimized Boinc clients for Linux, you will notice your mflops about double.

The only thing, this does not matter, since there are no optimized einstein binaries for Linux. The best solution is the use the windows binaries in Linux using wine.

> on Linux my mflops seem to be half what the windows machines running on the
> same processor gets.
>
> This is truly hard to believe.
>
> Have you tried the Intel Linux Compilers & sse2 instruction options ???
>

such things just should not be writ so please destroy this if you wish to live 'tis better in ignorance to dwell than to go screaming into the abyss worse than hell

S@NL Mark
S@NL Mark
Joined: 22 Jan 05
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The problem is that the

The problem is that the binary that really does the crunching is sent to you via the boinc client ie I've got an amd64 over here running 64 bit linux but the actual cruncher seems to be something 32 bits.

mark@ubuntu:~/.boinc/projects/einstein.phys.uwm.edu $ file ~/.boinc/boinc
/home/mark/.boinc/boinc: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.0, dynamically linked (uses shared libs), not stripped
mark@ubuntu:~/.boinc/projects/einstein.phys.uwm.edu $ file einstein_4.80_i686-pc-linux-gnu
einstein_4.80_i686-pc-linux-gnu: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.0.30, dynamically linked (uses shared libs), not stripped
mark@ubuntu:~/.boinc/projects/einstein.phys.uwm.edu $ uname -a Linux ubuntu 2.6.10-5-amd64-generic #1 Tue Mar 15 14:59:03 UTC 2005 x86_64 GNU/Linux

I really wonder if it makes sense running optimize boinc clients

Regards
Mark

Seti-Cruncher
Seti-Cruncher
Joined: 9 Feb 05
Posts: 70
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> I really wonder if it makes

Message 8745 in response to message 8744

> I really wonder if it makes sense running optimize boinc clients

It does because it affects the claimed credits which, in turn, affects the credits awarded - not only for you but for the others that crunch the same units.

As for crunching for Einstein, I have, along with many others, dumped it as it is too Linux-unfriendly and they refuse to release the source code to allow us to improve the situation.

Sad but true. :(

Be lucky,

Neil

Paul D. Buck
Paul D. Buck
Joined: 17 Jan 05
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> > I really wonder if it

Message 8746 in response to message 8745

> > I really wonder if it makes sense running optimize boinc clients
>
> It does because it affects the claimed credits which, in turn, affects the
> credits awarded - not only for you but for the others that crunch the same
> units.
>
> As for crunching for Einstein, I have, along with many others, dumped it as it
> is too Linux-unfriendly and they refuse to release the source code to allow us
> to improve the situation.

I just spent some time looking, and I did not see times that were too out of line of what I am getting on my machines. Heck, my best performing system time wise for almost all projects is my G5 which is running OS-X which is Linux ...

As far as not releasing the client, that is their option. Though I think I remember Bruce saying that they may get some expertise from the Participant population to try to address these concerns.

I grant that the spread from my slowest to fastest is over 3 hours (7:43 to 11:02 average processing time), but this is very clearly shown to be more of an issue of architecture, at least to me.

For example, my best performing systems are the 2.8 GHz Intel P4 and the G5. And the one thing in common that these have is that they are single threaded processors. The HT processors have times of 10:49, 11:02, and 10:50 ...

Now, my FIRST guess would be that they are running into some kind of contention problem. This could be in either the CPU/FPU or it could be cache "thrashing" ... because there is not a substantial difference in the processing times of my 3.2 GHz processors over the motherboard change, my best guess then points to contention of the FPU. If it was a cache problem I wouild have expected to see a higher difference between the single channel memory vs. dual channel.

ANd Mark, the best reason to run optimized programs is to get more done in the same unit time. That is why I am so intrested in the optimization work going on with SETI@Home, once they get some stuff validated and in general "production" the intent is to move the optimizations into the baseline code.

But, the common routines that are developed could be used by other projects as they "tune" their Science Applications.

Darren
Darren
Joined: 18 Jan 05
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> I just spent some time

Message 8747 in response to message 8746

> I just spent some time looking, and I did not see times that were too out of
> line of what I am getting on my machines. Heck, my best performing system time
> wise for almost all projects is my G5 which is running OS-X which is Linux

Most of my linux results have already dropped off the database (as I'm one of those who has also stopped running einstein on my linux systems) but the following are the same computer, booted in windows vs. linux - and there are substantial differences in the times.

http://einsteinathome.org/host/44709/tasks

http://einsteinathome.org/host/66491/tasks

About 10.5 hours average in windows, and about 18 hours average in linux.

Wurgl (speak^Wcrunching for Special: Off-Topic)
Wurgl (speak^Wc...
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> About 10.5 hours average in

Message 8748 in response to message 8747

> About 10.5 hours average in windows, and about 18 hours average in linux.

Expect 13.5 hours on Linux (hopefully) soon.
Maybe Windows will be faster too, maybe ... but this is another job.

Seti-Cruncher
Seti-Cruncher
Joined: 9 Feb 05
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Credit: 7,114
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> I just spent some time

Message 8749 in response to message 8746

> I just spent some time looking, and I did not see times that were too out of
> line of what I am getting on my machines.

The subject was the BOINC client. There is still a substantial disparity between OSs on the benchmarks - therefore the optimised clients are very worthwhile.

> Heck, my best performing system time
> wise for almost all projects is my G5 which is running OS-X which is Linux

OS X is not Linux. It is based on BSD Unix which is a very different animal. ;)

> As far as not releasing the client, that is their option.

Of course it's their option - just as it is mine not to crunch Einstein. ;)

If it's any consolation to anyone, Predictor is even worse to Linux users and that gets my thumbs-down too. :(

Be lucky,

Neil

G Thomas Wilson
G Thomas Wilson
Joined: 5 Mar 05
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> If it's any consolation to

Message 8750 in response to message 8749


> If it's any consolation to anyone, Predictor is even worse to Linux users and
> that gets my thumbs-down too. :(

Predictor recently made some substantial changes for the better.

I've only returned one 0.0 in the past week. The other returns have received full credit - Over 1200 credits in the past few days.

I still can't place my old AMD-K6 box on it without client errors though. No big loss. It's about as computationally gifted as your typical mall rat.


Seti-Cruncher
Seti-Cruncher
Joined: 9 Feb 05
Posts: 70
Credit: 7,114
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> > > If it's any

Message 8751 in response to message 8750

>
> > If it's any consolation to anyone, Predictor is even worse to Linux users
> and
> > that gets my thumbs-down too. :(
>
> Predictor recently made some substantial changes for the better.

Yep, they finally updated the server software. :)

> I've only returned one 0.0 in the past week. The other returns have received
> full credit - Over 1200 credits in the past few days.

I'm happy to say that I never had that problem. However, the Linux client takes 50% longer to complete a WU than the Windows version on my machines and, because Linux hosts get lumped together, the credit awarded tends to be very low due to most Linux users not running optimised BOINC clients.

Whilst I appreciate that it should be the science that matters, it is the competitive streak in me that keeps me crunching. ;)

Be lucky,

Neil

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