a-squared (a2) uses 620kB memory for realtime protection: http://www.sevenforums.com/system-security/56018-squared-uses-620kb-memory-realtime-protection.html
it seems to vary a little bit, depending on exactly what i´m doing,
1 hour ago it was 780kB, right now it´s 992kB.
but it stays below 1MB, doing it´s job in the background, can´t be much better can it ?
scanning: ~110MB, might go up to 180MB
a-squared (a2) is also very good at detecting, and has received several awards.