Ubuntu equally fast as Gentoo....WHAT???

[dE_logics]

I compiled lpaq9m.cpp (a compression tool) with -mtune=athlon64 -O3, then compressed a 10 MB file, it was talking around 54 seconds to compress on Gentoo AND Ubtuntu...this is what's bugging me...there should have been an advantage in the performance front (at least 10%) when compiling the whole OS from source!!

-------Verdict--------
Nope. I measured the startup times and saw Gentoo to be pretty fast.

lpaq9m.cpp might not get an optimization since it's too small.

[slycordinator]

The fact that you think there should be "at least a 10% increase in performance" is truly lol-worthy.
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My political stance/bias
slycordinator != slycoordinator

[dE_logics]

So the only advantage are the USE flags...ok they have a significant contribution, but I was wondering about the compile time optimization........no difference?

[StringCheesian]

[aidanjt]

This surely has to be a troll thread.
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[slycordinator]

[dE_logics]

It would have been a good idea to place this thread in the chat area........mods....pls do so.

Have a look -

http://www.linux-mag.com/id/7574/1/

So it DOES matter...I use blender...so I have major advantage in FPS.



I was wondering even if the optimization is about 2% per library/binary, then also it would sum up to a very large quantity for the whole system (use calculus theories or sorta like chaos theory).


I see Gentoo as VERY fast...no doubt, it's placebo effect...it's real and VERY significant I can count it.

Actually it's more than what difference I expected.

Furthermore, I heard Ubuntu binaries are compile with Os flag (the difference was 5 to 7% with lpaq9m sources)...now all this is an advantage in Gentoo.

To add more factors...I use a usual athlon X2...if it was an atom processor...or some unusual processor like the top notch phenom, xeon or i7 (etc....) there would have been a significant difference.

[dE_logics]

blank---------

Posted this by mistake.

[Azdo]

...and maybe the bottleneck is not in the CPU but in the I/O performance of the hard disk.

[dE_logics]

[i92guboj]

Moved from Portage & Programming to News & Announcements.
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Gentoo Handbook

[i92guboj]

Sorry for the first move, my browser did something strange in the middle.

Now: moved from News & Announcements to Gentoo Chat.

As for the thread: if you are using Gentoo because of the gain of performance, you are probably using it for the wrong reason. As said:

• most distros nowadays use worthy architectures, no longer 386-only object code
  
• most uber-specific compile flags are only noticeable in very specific programs, depending on the task they do and *how* do they do it
  
• anyway your cflags are really not that special (note that I am not saying they should be, setting crazy CFLAGS globally is a bad thing)

Sure you could tune up CFLAGS for each specific package (on a given architecture and for a given configuration) to get a slight improvement (slight, most times). Is is worth your time? No.
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Gentoo Handbook

[NeddySeagoon]

dE_logics,

[i92guboj]

I didn't even notice before, but note that "-mtune" doesn't really do that much optimization. If you truly want to measure how it can vary from code compiled for athlon64 to code compiled for a generic x86_64 cpu, you should be using -march, which truly optimizes the code breaking the compatibility with anything that's not that concrete cpu. Otherwise you are compiling a generic binary that will run on any x86_64 cpu.

Also, note that 64 bit cpus are really on early stages, compared to x86. The kind of performance difference that you can expect from compiling nowadays for x86_64 to athlon64 is the same difference you could expect between compiling for 386 or 486 back on its day... In other words: next to nil.

Once we have 6th generation x86_64 bit cpus sure that there will be a difference between that chip and a basic x86_64.
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Gentoo Handbook

[wswartzendruber]

[djdunn]

[NeddySeagoon]

Moved from Gentoo Chat to Off the Wall.

Its not gentoo related any more
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Gaff]

the reason I started using Gentoo back in the days of pre-1.4 was that I could get 2.5 kernel and different threading system (the one before nptl, whatever it was called) by simply emerging stuff I needed.

At the time I was sitting with redhat at work, and installing anything useful was a nightmare. Like codecs, recompiling glibc, etc etc.
Portage and USE flags were pure bliss in comparison. The fact that you could tinker with CFLAGS was interesting, but not the main issue.

[energyman76b]

also intel broke compatibility from the go with not implementing the full 64bit spec. Intel is a bunch of jerks - so no surprise.
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[dE_logics]

[dE_logics]

[energyman76b]

[vputz]

The real advantage of Gentoo is in flexibility, not speed. If you get an extra bit of speed with optimization, that's a pleasant side effect, but not really the primary benefit.

[poly_poly-man]

just make sure your CFLAGS include -fzomg-optimized, -mtune=so-fast and -O9.
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iVBORw0KGgoAAAANSUhEUgAAA

avatar: new version of logo - see topic 838248. Potentially still a WiP.

[tylerwylie]