Since CIS 3.5 got updated to 3.8 internally (quite long enough ) on feb 19 , i noticed an increase of about +25 mo on memory usage and also a certain periodical impack on cpu. I did not change any settings. Firewall and D+ set to Safe mode.
The memory usage increased very little due to a few more components added (e.g. Memory Firewall, Threatcast) but nowhere near +25megs. Do you mean when idling, scanning, etc?
Right now idling, my two cfp.exe and cmdagent.exe CIS processes are using a total of 6megs.