0patch Agent is designed to inject a dynamic load library (DLL) into each running process so that it can then apply and un-apply micropatches in that process. While there are some processes that don't let themselves get injected this way, most processes will spend an additional 600-700 KB of memory each for hosting that DLL. On a typical Windows 10 system with ~100 running processes this means a memory consumption of 60-70 MB.
(Note that we're planning to redesign 0patch Agent such that it will not require injection into processes, which will eliminate this cost.)
In addition, 0patch Service and 0patch Tray, which are running in the background, consume around 10 MB of memory each.