Re: Is it possible to set the performance in Camera Raw, like in PS? I have problems with the performance of the adjustment brush. It is a very bad workflow.

Since you haven't specified the version of your OS nor that of Photoshop and ACR, I'll take a crack at answering your question.

I see no such delay in ACR 8.5 running under Photoshop Mac 13.0.6 and OS X Lion 10.7.5.

If you have newer stuff, we have wasted your time and mine.

Please read this FAQ for advice on how to ask your questions correctly for quicker and better answers: 

http://forums.adobe.com/thread/419981?tstart=0

Thanks!