Well, if your using windows.

1.Press control+alt+delete.

2.Find the "PROCESS OF MAYA BATCH RENDER"(it should show a fast processor amount, 50% in you case)

3.Right click on the "MAYA BATCH RENDER" process and go down to set priority. Then choose either high or realtime. Be careful though, this hogs ALOT of RAM, and can slow down windows so much that it takes around ten seconds to just move you mouse an inch. Ughh.


Hope it all works.


PS. Make sure you choose the batch render process not just the maya process.