Updated to the latest version and noticed DarkMX was eating over 12 GB of RAM with my full library (~2.75 million files). I don't run any channels, just sharing. That's with the app sitting in the background.
Started digging into it and ran a direct comparison with Nicotine+ sharing the exact same folders.
With ~900,000 files:

DarkMX: 6.3 GB
Nicotine+: 594 MB

Same data, both idle in the background, almost 11x difference.
I tested at a few different library sizes and it scales at about 7 KB per file. Nicotine+ is under 0.7 KB. The shared.dat files on disk only total 179 MB, so the problem seems to be how the index is stored in memory. It's inflating massively when loaded.
I only caught this because I have 64 GB of RAM but use ~40 GB for PrimoCache. DarkMX's was causing OOM errors and broke indexing in Directory Opus and Explorer.

Also ran into some issues while testing:

Trying to remove a large share from the UI froze the app
Had to delete library.dat to get it to start again after force-quitting

Saw thread #160 mentioned similar problems in v1.41 but didn't see a fix. Is there anything planned, or a setting I'm missing?

What OS?
how many channels are you in?
do you have many users downloading from you?

I have 9.24TB in 115,712 files in my library and that uses 4.1GiB of memory. I am also in 12 channels, 3 of them I am the owner.

Windows 10 IoT LTSC.

I am in 13 channels. Only 9 host files. I am not an owner in any of them.

Right now no one is downloading from me. Sharing 8.2 TB from 899,813 files. RAM usage is 6.2 GB.

I notice you have less tb's but more files that I do, do you have lots of small files. I think they take more ram.