In the 2.6 kernel, IA-64-support has been fully integrated into the official kernel released by Linus. It is therefore no longer strictly necessary to apply the patches from this directory. In particular, if you can't find an ia64 patch for the kernel you want to try out, just go with the official kernel and you'll probably be OK. You can also check this web-page to see what the current build status of the official Linux kernel is: http://www.gelato.unsw.edu.au/kerncomp/ On the other hand, Linus himself doesn't test the kernel for IA-64, so it is generally safer to use a kernel with the matching IA-64 patch from this directory applied when possible.