machine: 2011 macbook pro 15"
client version: 3.0.0-rc2, 3.0.0
os: osx snow leopard

I started using teamspeak on osx recently by installing 3.0.0-rc2. I noticed that the ts3client was was using anywhere from 75-110% of a processor core. I hoped that the 3.0.0 release would solve the issue, and at first it appeared to. But as I got ts3 setup as before, the issue came back just as it was.

Here's the workaround.

By default, the ts3 client window has 3 panes that can be resized or hidden:
left (names and channels)
right (server and channel info)
bottom (messages and chat)

It turns out that it is specifically when the bottom pane is hidden that the processor utilization jumps. Upon dragging it visible again, utilization goes back to normal (~6.5%). It is easy to replicate the issue as many times as you like. Hiding the left or right panes does not affect processor utilization.

I don't need it, but for now I'm leaving the bottom pane visible and as a result teamspeak 3.0.0 behaves as expected.