Hello, I started to build rpms already long time ago, but being biologist I really miss most of the IT-background. Please if its possible give me feedback if I'm proceeding well or not in the following two cases: I have a centrino (i686) laptop and if I build something for my own computer, I do rpmbuild -ba --target i686--Linux something.spec , but for my girly, riding a 900MHz athlon doing (still on my own comp) rpmbuild -ba --target athlon--Linux something.spec I have the following in my .rpmrc i686 -O3 -march=i686 I heard about -mtune and got a little bit confused, maybe that one I would need to include as well?! I don't mind not to optimize a lot, but at least the i686/athlon differentiation I would like to keep as possible. Thank you for any tips and ideas, Pelibali Ps. Just theoretically, but which command/.rpmrc I would use if I would build on the athlon for athlon OR centrino/i686? ((e.g. athlon -O3 -march=athlon ))