iStat Menus - "An advanced Mac system monitor for your menubar."
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.
iStatistica Pro - System monitor. Reinvented. 💻 🖥
HWiNFO - Professional System Information and Diagnostics. Comprehensive Hardware Analysis, Monitoring and Reporting for Windows and DOS. FREEWARE. download. Advertisements.
Stats - Simple macOS system monitor in your menu bar.
AIDA64 - AIDA64 is a system information, diagnostics and benchmarking solution for Windows PC.