CPU-Z - CPU-Z is a freeware that gathers information on some of the main devices of your system : Processor name and number, codename, process, package, cache levels.
AIDA64 - AIDA64 is a system information, diagnostics and benchmarking solution for Windows PC.
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.
Hardinfo - Hardinfo is a system information and benchmark tool for Linux.
Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
CPU Info - CPU Info provide main information about hardware and software of your device. You can get: