Windows: Open Task Manager > Performance > CPU
Windows: Press Win + R, type msinfo32, and press Enter
Windows: Open Command Prompt and run wmic cpu get name, maxclockspeed, numberofcores, numberoflogicalprocessors
Windows: Open PowerShell and run Get-CimInstance Win32_Processor | Select-Object Name, MaxClockSpeed, NumberOfCores, NumberOfLogicalProcessors
macOS: Click Apple menu > About This Mac
macOS: Open System Information > Hardware > CPU
Linux: Run lscpu in Terminal
Linux: Run cat /proc/cpuinfo in Terminal
Linux: Run sudo dmidecode -t processor in Terminal
BIOS/UEFI: Restart the computer and enter BIOS/UEFI setup
Mobile: Check device specifications in Settings > About phone/About device
Mobile: Use a system info app from the app store