Gentoo performance comparison

[incognito_xl]

How big will be the performance gain if you install Athlon-XP files instead of
- i686
- i386
files on an AMD Athlon XP machine? Any experiences?

[energyman76c]

What are you asking for?

I do not really understand your problem, so I start with some possibilities:
you have an athlon-xp, and you are contemplaiting about CFLAGS, -march=athlon-xp is fine, CHOST i686-pc-linux-gnu.

or do you want to install a binary programm that comes as i386 packet and a i686 packet? Then you should use the i686 packet, it should be slightly faster.

or there is only a i386 compiled version and you are worried about the performance you are loosing: in general it is not enough to be worth worrying

[iggy]

I found that there is almost no difference in when -march is set to i686 or athlon-xp, and small improvement of athlon-xp over i386.

Although optimisitaion for the particular CPU can help with some programs, generally it is too small to really worry about for majority of them.

My CFLAGS are almost always -march=athlon-xp O2 -pipe -fomit-frame-pointer, but I do sometimes use -O3, and some other options depending on the package and desired performance.

[incognito_xl]

Thanks for replying. This is what I wanted to know!

[yujen]

there are a few exceptions though...

Openoffice
Mozilla
Xfree86

and a couple of other larger applications will benefit quite well from an optimized build... if you tried very agressive optimizations you also risk the chance the application will be broken... so be a little careful.

[energyman76c]

Hi,

> if you tried very agressive optimizations you also risk the chance the application will be broken... so be a little careful.

or slower.
Especially O3 is sometimes a lot slower than O2 or Os. An app, that needs a lot of cache for its code, has not much room for data, and most optimiziations increase the codesize a lot.

[davidgl]

At least two of our regular correspendents are going to be happy with the announcement of a new gentoo release on Distrowatch.com.
DGL.

[energyman76c]

Hi,

and who are they?

I am gentooer but not 'happy', because releases are only important for the live/install cds ;)

[energyman76c]

hm, I read the article at distrowatch.

Were you talking about the new G5 port, when you wrote, that two memebers would be happy?

Ok, that is a reason to celebrate ;)