Gentoo Optimizations Benchmarked

[Fitzcarraldo]

Portage users out there might find this article in Linux Magazine interesting: Gentoo Optimizations Benchmarked.

[DontPanic]

That was a really interesting (and surprising) link.

Thanks for posting that.

I've read GCC developers M/L posts where they swear up and down that O2 is faster than Os. The rationale is that if the GCC devs discover an Os size optimization that makes things faster, they'll include it in O2.

These results didn't bear that out.

I was also surprised at the QGears2 results, since they were using nVidia drivers. I'd always found the nVidia binary drivers usually had more influence on the speed than the way the system was compiled.

[Fitzcarraldo]

A second article was issued on 1 March 2010:

Gentoo Optimizations Benchmarked - Part 2

[DontPanic]

It doesn't surprise me that there is a point of diminishing returns in optimization.

But one of the reasons I left Debian was their almost religious insistence that there was little difference between i386 and i686.

The other main reason for getting away from Debian was the inability to control the mountains of dependencies.

I feel smarter now. This article seems to confirm both of my perceptions.

[Fitzcarraldo]

^Yes, it's another fascinating article (I like this type of article, with plenty of in-depth analysis). A couple of quotes from the second article stand out to me:

The main benefit that Gentoo has over Ubuntu is the ability to fine tune the system, leaving out what you don’t want and including those components you do. This means the system can be more lean, which results in better performance and less overhead.

He was benchmarking against Ubuntu, hence his specific reference to it in the article, but for "Ubuntu" one can read "a distribution with binary package management".

At its core, Gentoo is about flexibility, not about optimizing code to run the fastest. It’s about being able to make your system whatever you want it to be, through the use of USE flags.

I've always liked the Gentoo philosophy and, with Portage getting better and better over the last couple of years, I'm finding SL/Gentoo a really usable OS. I don't have Entropy installed on my main machine any more, just Portage, so can't really comment on that side of things, but the Gentoo source package approach makes perfect sense to me. The vast majority of packages don't take that long to compile on modern hardware, so I don't find the waiting such a drag (although I still draw the line at merging openoffice, and merge openoffice-bin instead). It's not difficult to see why the Chrome OS developers switched to Portage, is it? The fine-grained control does it.

[tripleninez]

I've always liked the Gentoo philosophy and, with Portage getting better and better over the last couple of years, I'm finding SL/Gentoo a really usable OS. I don't have Entropy installed on my main machine any more, just Portage, so can't really comment on that side of things, but the Gentoo source package approach makes perfect sense to me. The vast majority of packages don't take that long to compile on modern hardware, so I don't find the waiting such a drag (although I still draw the line at merging openoffice, and merge openoffice-bin instead). It's not difficult to see why the Chrome OS developers switched to Portage, is it? The fine-grained control does it.

this is what i want to do - remove entropy and use portage only. how did you accomplish this, i just posted about this.
i wish to remove entropy and be able to use /etc/make.conf without having hassles caused by entropy/binaries/downgrade issues.

i am new to Sabayon, and love the redhat installer + gentoo, but i need to ditch entropy and make this a portage only system. my thoughts were to install the CoreCD, remove entropy - it's configs that conflict...
then build my system with a combination of ICC and GCC where required..

any help would be great.

ts9

[Fitzcarraldo]

^See Re: how do i uninstall entropy? for instructions on how to remove Entropy.

[dE_logics]

These things depend on your machine type, and the GCC devs do know what they are doing; these people are at a very low level, that means they understand EXACTLY what the processor does, the ram does and how a software works on it. By this they conclude -O2 is the best.

What makes Gentoo fast are the USE and LD FLAGS, USE flags mostly cut down dependencies of loaded modules making the program swift and fast. If you've set use flags for functionality, then you'll loose out on speed.