fcp beach balling with mak 3 footage

i have converted my canon mak 3 footage to apple pro res 422, LT and proxy, tried all three and inspite of that fcp starts beach balling and then is completely non responsive every time i try to play them. I am a slightly newbie editor so I may not have my system settings right. although it worked completely fine with mak 2 footage all this while. can anyone help?

What Mac, how much RAM, hard drive set up, where are Events & Projects?

Verify that all drives have at least 10-15% of their capacity as free space.