I have a machine with four AMD Opteron(TM) 6272 processors: http://www.amd.com/us/products/server/processors/6000-series-platform/6200/P... I use 'virsh nodeinfo' to determine the amount of physical CPUs, and CPU cores. What values should I be looking at in the output of nodeinfo to determine this? With 1.X libvirts the output values have changed from 0.9.4: 0.9.4: [root@host ~]# virsh nodeinfo CPU model: x86_64 CPU(s): 64 CPU frequency: 2099 MHz CPU socket(s): 4 Core(s) per socket: 8 Thread(s) per core: 2 NUMA cell(s): 1 Memory size: 24713980 kB [root@host28 ~]# 1.0.1: [root@host ~]# virsh nodeinfo CPU model: x86_64 CPU(s): 64 CPU frequency: 2099 MHz CPU socket(s): 1 Core(s) per socket: 8 Thread(s) per core: 2 NUMA cell(s): 4 Memory size: 24713980 KiB [root@host28 ~]# As you can see, the CPU socket and NUMA cells values have changed in these two versions, on the same machine. To get the physical CPU count, is it safe to assume this? Numa cell(s) X CPU Socket(s) == physical CPUs present However, I am not positive what formula I should use to determine the CPU core count. On this processor, it has 16 cores. Would that mean I can do this? Core(s) per socket X Thread(s) per core: == CPU cores Thanks in advance for clarifying.