Fact: take 3 distros, install to the reccomended settings (as far as is practical) and see which is faster. Gentoo was slowest. At the time (is it still the case?) -O3 was being reccomended for gentoo in general, celerons in particular (was a few months back now!) This flag has a rather drastic effect on performance, particularly with celeries. Its not just this test, there have been a couple of posts where people who have dual booted with other distros and find gentoo slower until properly tuned (did the last poster with the custom application eventually get gentoo to run faster than debian?)
I did some tests afterwards (not on the same machine unfortunately) and found that in general, gentoo-sources is slightly faster than open-mosix (no thread migration) and vanilla kernels (hey, I gotta download this stuff through a modem!). Might be hardware dependent but I think this will hold up in other configs. pre-empt etc on/off made little/no difference. It is also worth noting that these machines were all new installs and had no "cruft", extra services running so these features would have little effect. So the idea that using the recommended (at the time) gentoo-sources kernel for performance was ok. This time around I chose gs-sources, mainly for the new hardware support, but also it seemed to perform better than gentoo-sources which had not been updated at the time. So unless you have some specific tests which are biased to some kernel feature, you are not going to see much advantage/disadvantage there. Attempts were made to use the gentoo kernel on the other machines (debian), but proved too much work for the time involved. But, whats the point of using the same kernel on each machine when gentoo recommend gentoo-sources, Mandrake recommends ... It would have been nice to check each distro with a vanilla kernel just to see what would happen, but there were only so many hours in that day. The test we did early last month (www.linmagau.org) showed that with a better match of CFLAGS to hardware, you can expect about a 10% gain (sometimes, if the CFLAGS and hardware and application are a good match) - but can lose it by making poor choices elsewhere. 10% is not to be sneezed at, but its hardly earth shattering either. As I have stated previously, these are empirical tests, not definitive scientific ones but should hold up in the real world when doing the kind of work that I and the others do in our day jobs. BillK On Tue, 2003-11-04 at 02:56, Stroller wrote: > On Nov 2, 2003, at 10:13 pm, William Kenworthy wrote: > > > > There was actually a lot of misinformation and pure rubbish spread on ... > > > > There was some good reasons for that result > > And you address the one I had in mind by using the same kernel on all > three machines in your "revisited" article. > > But to suggest, as the original article did, that "these distributions > are faster than Gentoo" is NOT empirical when the distros tested have > such a glaring difference between them. As you know, the Gentoo-sources > (with pre-empt patches) kernel was tested in the original article > against another with Redhat's patch-set. > > Stroller. > > > -- > [EMAIL PROTECTED] mailing list -- William Kenworthy <[EMAIL PROTECTED]> -- [EMAIL PROTECTED] mailing list
