A number of benchmarks show a significant performance loss on 32bit ubuntu over 64bit [1], on the same hardware. This is partially due to restrictions on the instruction set and partially due to worse instruction scheduling (others reasons include register width and count, for moving data and calling convention).
Just how much user experience do we trade away for i386/i486 legacy compatibility these days? If (eg) 1.0% of 32bit Ubuntu users have i586-only processors, how about setting the default compile flags to -march=i586 and -mtune=pentium3 in principle? This seems like good value to tweak end-user performance/experience a bit, am I missing something, or should we just not care? (does any of this apply to x86-64, eg -mtune=core2 or k8?) --- [1] http://www.phoronix.com/scan.php?page=article&item=ubuntu_osx_64bit&num=8 -- Daniel J Blueman -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
