For XPS 15 9550:
$ dmesg |grep microcode [ 0.000000] microcode: microcode updated early to revision 0xd6, date = 2019-10-03 [ 1.948537] microcode: sig=0x506e3, pf=0x20, revision=0xd6 [ 1.950991] microcode: Microcode Update Driver: v2.2.
$ dpkg -l|grep micro ii amd64-microcode 3.20191021.1+really3.20181128.1ubuntu1.1 amd64 Processor microcode firmware for AMD CPUs ii intel-microcode 3.20191115.1ubuntu0.19.04.2 amd64 Processor microcode firmware for Intel CPUs
For XPS 15 9550:
$ dmesg |grep microcode
[ 0.000000] microcode: microcode updated early to revision 0xd6, date = 2019-10-03
[ 1.948537] microcode: sig=0x506e3, pf=0x20, revision=0xd6
[ 1.950991] microcode: Microcode Update Driver: v2.2.
$ dpkg -l|grep micro 1+really3. 20181128. 1ubuntu1. 1 amd64 Processor microcode firmware for AMD CPUs 1ubuntu0. 19.04.2 amd64 Processor microcode firmware for Intel CPUs
ii amd64-microcode 3.20191021.
ii intel-microcode 3.20191115.