Also the Task Manager that comes with Windows. Guess these are listed in my order of preference. Core Temp is best if it supports your CPU. Gives peak temperature reading so you know how hot the core got while you were making a sandwich.
Hmm, 8 cores. Is that a server? Never saw 8 cores in a PC. What CPU is that? Just curious. One way to check it is to install "Core Meter" in the sidebar.