7/14/2023 0 Comments Linux command cpuinfoIf "books" are in play on a given Linux system ( does anybody know when and how?), the physical-CPU-count command may under-report (this is based on the assumption that lscpu reports IDs that are non-unique across higher-level entities e.g.: 2 different cores from 2 different sockets could have the same ID). Tip of the hat to for helping to correct the physical-CPU-count lscpu command.Ĭaveat: lscpu -p output does NOT include a "book" column (the man page mentions "books" as an entity between socket and node in the taxonomic hierarchy). Note that BSD-derived systems other than macOS - e.g., FreeBSD - only support the hw.ncpu key for sysctl, which are deprecated on macOS I'm unclear on which of the new keys hw.npu corresponds to: hw.(logical|physical)cpu_. # Counting the *unique* cores across lines tells us the # - in the case of hyperthreading - more logical CPUs. # Linux: The 2nd column contains the core ID, with each core ID having 1 or # which tells us the number of *logical* CPUs. # Linux: Simply count the number of (non-comment) output lines from `lscpu -p`, # Number of LOGICAL CPUs (includes those reported by hyper-threading cores) # systems, currently disabled (offline) CPUs are NOT # `-p` reports *online* CPUs only - i.e., on hot-pluggable # generated by `-p` to support older distros, too. # formats, but we stick with the parseable legacy format # Note: Newer versions of `lscpu` support more flexible output # Linux: Parse output from `lscpu -p`, where each output line represents # number of *currently* available ones see below. # available dropping the "_max" suffix would report the # current power-management mode could make *fewer* CPUs # available number of CPUs is reported, whereas the # CAVEAT: Using the "_max" key suffixes means that the *maximum* # macOS: Use `sysctl -n hw.*cpu_max`, which returns the values of With each level comprising 1 or more instances of the next lower level. Linux uses the following taxonomy, starting with the smallest unit: Non-hyper-threading cores each correspond to 1 CPU, whereas hyper-threading cores contain more than 1 (typically: 2) - logical - CPU. Terminology note: CPU refers to the smallest processing unit as seen by the OS. Uses lscpu for Linux, and sysctl for macOS. Here's a sh (POSIX-compliant) snippet that works on Linux and macOS for determining the number of - online - logical or physical CPUs see the comments for details. Getconf _NPROCESSORS_ONLN / getconf NPROCESSORS_ONLN doesn't distinguish between logical and physical CPUs. Again, you will also see a more complex outputs.The problem with the /proc/cpuinfo-based answers is that they parse information that was meant for human consumption and thus lacks a stable format designed for machine parsing: the output format can differ across platforms and runtime conditions using lscpu -p on Linux (and sysctl on macOS) bypasses that problem. Other option, you can also manually display the contents of the cpuinfo file which is located under the the “/proc” directory by typing cat /proc/cpuinfoon the terminal. Plus, they also display far more complex outputs. However, those two tools are not installed by default in most Linux distro. In addition to lscpu, there are also several other tools you can use to check the CPU info of your computer. CPU(s): tells the number of cores of your CPU.Architecture: tells the type of your CPU. x86_64 means you have a 64-bit processor.Some of the key columns from the table above are: To use the tool, simply type lscpuon the terminal and you will see the following outputs. This tool works by gathering the CPU info from sysfs and “/proc/cpuinfo”. You don’t have to be root to run it. It is also installed by default. In most Linux distros, lscpu can be used by all users. The CPU-related info displayed by this tool include the architecture, the number of cores, processor model, processor vendor, clock speed and so o. This tool displays the complete CPU info in readable format. Lscpu is the standard tool to check the CPU info in Linux. The command you are going to use is lscpu. As I said, you can check the CPU of your Linux computer with a single command. Command-line based tools display more accurate info. While there are many GUI-based tools to check your CPU info, command line tools are still the best option to check the hardware-related info on your computer. In Linux, you can get the complete information about your CPU in a single command. Did you ever wondered about the CPU info of the computer you are using? Like the architecture, the number of cores, model and so on.
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