I have a brand new bespoke iMac (4 GHz Intel Core i7). Since upgrading to OS Sierra a few of my Ps CC tools have become really slow regardless of file size. Magnifying tool is the worst. I just did the very latest CC update but same old problems. If I click on the magnifier then go to file in under 2 seconds it won't work. I have to wait a few seconds for it to catch up. Any fixes?