On 20/06/08 22:08, Donald Tripp wrote: > While compiling some packages, i saw that it was using mtune=pentium4, > even though my system is a pentium3. Where can I set this? This is set on a per-architecture level (see /usr/lib/rpm/redhat/rpmrc for who gets what), and ends up in the 'optflags' macro. You could either specify something like rpmbuild --target i586 ... or explicitly pass in your own optimization flags via rpmbuild --define 'optflags %{__global_cflags} -whatever' you can set this permanently e.g. in your ~/.rpmmacros file: %optflags %{__global_cflags} -whatever (i386 is so widely used to mean "all 32bit" that optimizing for the common = >Pentium3 case makes sense. Please note that -mtune=pentium4 code will still happily run on a pentium3, just perhaps slightly slower - and if you'd care about peak performance, you'd probably be running something else anyway..) regards jan