OK, I have a laptop with 3GB Ram, when I install Antergos KDE (no difference to Arch, it does the same) and I leave my laptop on for days and the RAM gets used up until the laptop freezes.

I had LXDE installed and there it didn’t happen.

Also a Debian stable XFCE version doesn’t do anything like this.

No prefetch is installed.

Anyone having an idea why my RAM gets filled up with cached stuff until my laptop freezes?

Cache should be droped before it freezes my laptop, but that isn’t happening.