Ever since updating to OS X Mavericks, Preview constantly eats up tons of CPU. As soon as I hear my fan start whirring, I check activity monitor and Preview is usually at ~100% usage. It's very easy to fix the problem by just quitting Preview and reopening it (no laggy spinning beach ball or anything), but often the problem comes back after a while.
What causes this and how do I fix it?
It does the same thing to me. In my case, however, it seems to happen when any window belonging to the Preview app has the find bar up. It doesn't seem to matter what the search string is or whether there are any occurrences of it in the document. It also doesn't matter if the window is frontmost or not, or if the window is minimized. In all cases Preview is using about 107% CPU - basically taking over one core. Once I click "Done" to dismiss the find bar and its associated sidebar, the CPU usage goes back to normal.
So if you notice the same pattern, the obvious workaround is to only have the find panel up when you're actively using it, assuming this isn't disruptive to your workflow.
