So I am using rust analyzer with a pretty large project in a cargo workspace - the project in question has around 830 deps - and noticed that rust analyzer is using nearly 13 gb:
Currently, there is no complete way to diagnose memory overuse problems (there used to be a command "rust-analyzer: Memory usage (clears database)", it's still there but it doesn't do anything. You can run rust-analyzer-binary analysis-stats your-project-dir and it will (among others) report memory stats, but it does not exactly resembles IDE usage scenario).
However, I believe 13gb is quite typical for a workspace that big.