On recent machine (88 cores + HT) running Xenial:
$ dpkg-query -W intel-microcode intel-microcode 3.20170707.1~ubuntu16.04.0
$ grep -E 'model|stepping' /proc/cpuinfo | sort -u model : 79 model name : Intel(R) Xeon(R) CPU E5-4669 v4 @ 2.20GHz stepping : 1
$ journalctl -k | grep microcode Aug 11 09:39:18 node14.mgmt.hre.local kernel: microcode: CPU0 sig=0x406f1, pf=0x20, revision=0xb00001e ... Aug 11 09:39:18 node14.mgmt.hre.local kernel: microcode: CPU175 sig=0x406f1, pf=0x20, revision=0xb00001e Aug 11 09:39:18 node14.mgmt.hre.local kernel: microcode: Microcode Update Driver: v2.01 <email address hidden>, Peter Oruba
It's probably not that relevant but I also couldn't find any regression on a very old Core 2 Duo (no new microcode) running Xenial:
$ grep -E 'model|stepping' /proc/cpuinfo | sort -u model : 23 model name : Intel(R) Xeon(R) CPU E3110 @ 3.00GHz stepping : 6
$ journalctl -k | grep microcode Aug 17 14:29:28 xeon kernel: microcode: CPU0 microcode updated early to revision 0x60f, date = 2010-09-29 Aug 17 14:29:28 xeon kernel: microcode: CPU1 microcode updated early to revision 0x60f, date = 2010-09-29 Aug 17 14:29:28 xeon kernel: microcode: CPU0 sig=0x10676, pf=0x1, revision=0x60f Aug 17 14:29:28 xeon kernel: microcode: CPU1 sig=0x10676, pf=0x1, revision=0x60f Aug 17 14:29:28 xeon kernel: microcode: Microcode Update Driver: v2.01 <email address hidden>, Peter Oruba
On recent machine (88 cores + HT) running Xenial:
$ dpkg-query -W intel-microcode 1~ubuntu16. 04.0
intel-microcode 3.20170707.
$ grep -E 'model|stepping' /proc/cpuinfo | sort -u
model : 79
model name : Intel(R) Xeon(R) CPU E5-4669 v4 @ 2.20GHz
stepping : 1
$ journalctl -k | grep microcode mgmt.hre. local kernel: microcode: CPU0 sig=0x406f1, pf=0x20, revision=0xb00001e mgmt.hre. local kernel: microcode: CPU175 sig=0x406f1, pf=0x20, revision=0xb00001e mgmt.hre. local kernel: microcode: Microcode Update Driver: v2.01 <email address hidden>, Peter Oruba
Aug 11 09:39:18 node14.
...
Aug 11 09:39:18 node14.
Aug 11 09:39:18 node14.
It's probably not that relevant but I also couldn't find any regression on a very old Core 2 Duo (no new microcode) running Xenial:
$ dpkg-query -W intel-microcode 1~ubuntu16. 04.0
intel-microcode 3.20170707.
$ grep -E 'model|stepping' /proc/cpuinfo | sort -u
model : 23
model name : Intel(R) Xeon(R) CPU E3110 @ 3.00GHz
stepping : 6
$ journalctl -k | grep microcode
Aug 17 14:29:28 xeon kernel: microcode: CPU0 microcode updated early to revision 0x60f, date = 2010-09-29
Aug 17 14:29:28 xeon kernel: microcode: CPU1 microcode updated early to revision 0x60f, date = 2010-09-29
Aug 17 14:29:28 xeon kernel: microcode: CPU0 sig=0x10676, pf=0x1, revision=0x60f
Aug 17 14:29:28 xeon kernel: microcode: CPU1 sig=0x10676, pf=0x1, revision=0x60f
Aug 17 14:29:28 xeon kernel: microcode: Microcode Update Driver: v2.01 <email address hidden>, Peter Oruba