Intel Microcode Update Utility for Linux The microcode_ctl utility is a companion to the IA32 microcode driver written by Tigran Aivazian . The utility has two uses: * It decodes and sends new microcode to the kernel driver to be uploaded to Intel IA32 processors. (Pentium Pro, PII, PIII, Pentium 4, Celeron, Xeon etc - all P6 and above, which does NOT include pentium classics). It also supports processors of the x86_64 architecture. * It signals the kernel driver to release any buffers it may hold. The microcode update is volatile and needs to be uploaded on each system boot i.e. it doesn't reflash your cpu permanently, reboot and it reverts back to the old microcode. To use this utility you need to compile the kernel driver (found under "Processor type and features"). The microcode itself can be found at http://downloadcenter.intel.com/default.aspx and should be placed under /lib/firmware/microcode.dat. To have the microcode updated each time at boot, start the included init script from /etc/rc.d/rc.local: if [ -x /etc/rc.d/rc.microcode_ctl ]; then /etc/rc.d/rc.microcode_ctl start fi