Hi there, I have a newish AMD64 machine. NForce4 chipset. Asus A8N-E motherboard. PCI-Express 16x graphics, etc. No matter what I try I've been constantly stopped from building a 2.6.13 kernel with Ingo's rt14 patch. Here's the error message: AS arch/x86_64/lib/copy_user.o AS arch/x86_64/lib/csum-copy.o CC arch/x86_64/lib/csum-partial.o CC arch/x86_64/lib/csum-wrappers.o CC arch/x86_64/lib/dec_and_lock.o CC arch/x86_64/lib/delay.o AS arch/x86_64/lib/getuser.o AS arch/x86_64/lib/putuser.o AS arch/x86_64/lib/thunk.o CC arch/x86_64/lib/usercopy.o AR arch/x86_64/lib/lib.a GEN .version CHK include/linux/compile.h UPD include/linux/compile.h CC init/version.o LD init/built-in.o LD .tmp_vmlinux1 drivers/built-in.o(.text+0x24acc): In function `acpi_processor_idle': : undefined reference to `tsc_c3_compensate' make: *** [.tmp_vmlinux1] Error 1 lightning linux # The 2.6.13 kernel builds fine before I apply the patch but fails afterward. I do not find the error message undefined reference to `tsc_c3_compensate' in Google so maybe it's just me and my kernel config. I've attached the config file zipped. I've tried some obvious stuff like completely disabling ACPI, etc., but I haven't found anything that works yet. Thanks in advance for any ideas. This has held up my new AMD64 machine being useful for a few weeks now. NOTE: I have tried other realtime kernels like ck-sources but so far I am having xrun problems. Possibly there is someone here successfully using this motherboard? If so please contact me on-line or off with info on your setup. Cheers, Mark