Way way way back before windows 10 was even a thing. There used to be a thing called all CPU meter and one for GPU as well.
They are great when you have dual monitor and want to know if CPU usage spiked a lot or what not while playing a game on the main monitor. It doesn't even hurt that you can see if a video game froze and crash on top of other usages.
However with windows 10 64 bit (gaming reason) being the main OS to be on now. Gadget cease to be a thing long ago because of security concerns which is understandable. However it does leave me without an alternative option that I am current aware of. I want it to be easy to move around across multiple-monitor so something like sidebar system resource monitor wouldn't be that good. Ditto for that tiny task manager icon on the taskbar. Especially since the taskbar are usually obscured by the game in fullscreen already anyway.
Heck at this point I would settle for something little less feature.
For reference:
http://addgadgets.com/all_cpu_meter/
http://win7gadgets.com/pc-system/gpu_meter_24.html
