If you look at how many virus signatures need to be at the ready, any antivirus better use RAM since leaving that on disk would cause the machine to work poorly.
So, in short, the more virus signatures, the bigger the overhead.
When using Bitdefender Free, I notice some memory readings as high as 175,000 - 205,000. and a commit charge of around 485 M/ 5596 M. Why should a high memory reading on such a small program without any features ?

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