No status bar and why is it consuming evermore ram?

I am new to avast! and have at least two questions.

  1. How long should a scan take of a 3tb hard drive with 800gb free? I wish there was some status bar, % completed or Time Left indicator.

  2. I have 32gb of RAM and when I started the scan 45 minutes ago only 10% was used and now it shows 100% is used. What is going on?

Thank you!