Which Idea on Linux there are two big problems - memory (which I failed to resolve :)) and overall performance. When I've just installed it, it wasn't usable on may box with four Xeon CPUs and four gigs of memory, and that fact surprised me a lot. After some time spent looking on Internet found several tips, which resolved most of my problems. First one is following java setting, which switches off storing images in pixelmaps:
Another thing is one of Linux file system settings, which disables update of accessed timestamp. I'm working with quite big projects, which have several thousand files and updating timestamp of each file access is unnecessary overhead. That feature is something which doesn't have lots of use and can be witched off, specially when you are running Linux as desktop. Just add following to your filesystem mount settings in fstab:
After that Idea became reasonably fast, but I must admit, on Win XP or Vista it still runs faster and uses less memory.
I'm running Fedora 10 with NVidia graphic drivers.
Udpate 2010.12: I've just installed Idea 10. It looks just awesome and it's much faster! Works brilliantly. Thanks to IntelliJ!