Start your Task Manager, click on the performance tab, on the bottom of the window click on Resource Monitor, click on the Memory Tab of the Resource Monitor, Press the Expand Down Arrow button on the Physical Memory Block, Observe your Standby Memory.

If your Standby Memory is high, like mine which was at 12gb allocated to Standby of my 16gb of RAM with only 20mb free, and 4gb in use, then this tool is for you.

Download RamMap free from microsoft. Download, extract, run. Click on the Empty Tab on top, select Empty Standby List.

This was awesome for my performance. I use it prior to launching GalCiv4, much smoother gameplay. My free memory stays around 8gb now instead of almost nothing.

https://learn.microsoft.com/en-us/sysinternals/downloads/rammap

Supposedly Standby Memory is memory the system holds onto for programs it thinks will run again soon but are not currently active. It is supposed to be available for programs currently running to utilize just as free memory but from my personal experience I agree with hundreds of online commentators it doesn't actually function that way. It holds on to  and denies RAM to your video games.

Clear it before you play.