Comment # 20 on bug 903874 from Takashi Iwai

Oh, I didn't expect so much my blind shot really hits.

For checking whether it's a kernel side regression or a microcode regression,
could you try the following?

- Test openSUSE 13.1 kernel and SLE12 kernel with the latest ucode-intel
(20140913) enabled

- Downgrade to openSUSE 13.1-Update ucode-intel package (20130906):
 
http://download.opensuse.org/update/13.1/x86_64/ucode-intel-20130906-6.2.x86_64.rpm

BTW, yes, recreating initrd is needed (unless it's triggered automatically by
rpm).  You can check the output of lsinitrd whether it includes the early
microcode or not.