So, I've recently made the switch from Deluge to KTorrent, due to Deluge going through some issues.

In any case, I've loaded about 200 torrents into KTorrent, and all was going well, until my RAM usage got so high that my computer essentially stopped functioning. So I had to get my way into a terminal and kill it from there. Now, whenever I start KTorrent, my ram jumps from an idle 1.5GB to 2.5GB immediately, and if I try to quit KTorrent through the GUI, it will jump to a computer-crawling 3.9GB RAM usage, and seems to be reading my HDD an AWFUL lot.

How can I stop this behavior?

Are you running all those torrents at the same time ?

Well, yes, I'm seeing them all. I mean, I'm not actively uploading them, but it's so that when someone else wants them, it's available to them. This is how I've always torrented. I don't "Queue Uploads" I just have 5 upload slots, but all my torrents seeding.

I have never run with that many torrents, so I'm not sure how much memory usage to expect in these situations. And as far as I know, there are no memory leaks, which could eat up all memory.

Can you do some experiments, and see what happens if you only run 25, 50, 100 and 150 torrents ?

I also don't think it is a good idea to run with that many torrents, there are limits on the amount of network connections, and with 200 torrents, a torrent on average may get only 3 or 4 peers.