Is iChat hogging a ton of RAM for you? The "File Transfers" window might be the cause.

(This post refers to iChat v4.0. I'm not sure if the same problem exists for previous versions.)

I get a lot of big files sent to me via IM - Photoshop files, Illustrator files, etc. I leave the File Transfers window open all the time, and I almost never clear it. It turns out, that's not a very good idea.

Each file transfer that you receive results in iChat immediately grabbing more RAM. And if you don't clear your File Transfers list, each file will continue to hog that RAM until you clear the list - even if you quit iChat and relaunch it. I ran a little test to prove it.

I sent myself 8 files totalling 2.4 megs:



In Activity Monitor, iChat was using 119 megs of RAM:



I then clicked the "Clear" button in iChat's File Transfers window:



iChat's RAM usage instantly dropped to 98 megs:



That means that only 2.4 megs of file transfers resulted in iChat grabbing 21 megs of RAM. You can imagine what leaving the File Transfers window uncleared for weeks would do. iChat was routinely hogging 600+ megs of RAM for me, which was really slowing my computer down.

So make sure you clear your File Transfers window often!