dood screw Avast, used it for awhile, it is mediocre at best (PITA), I have been using "Threatfire" for awhile now (at least a year) and no issues,
it is also free and does not use up crazy amount of recourse's, I most often shut it down when I go into AH ( from the task bar), but there have been times I totally spaced it out, and left it on, no noticeable difference. (no I don't have an UBER system either)
take my advice, at least try it out, you wont be disappointed.
INK