Thank you for your recent votes on the individual performance items. High memory and RAM usage is something we are continuously working to improve, and the team is hard at work on fixes.
If interested, you can find more details on how Teams currently uses Memory at https://docs.microsoft.com/microsoftteams/teams-memory-usage-perf.
An error occurred while saving the commentDavid Riches commented
Switching between different chats instantly hogs 1.2Gb memory and 60% cpu. Then drops back down to 500-600Mb memory after a few seconds. Not great.