I purchased a used iMac which I wanted to use exclusively for video work and have run into a few concerns. I have found that I need to wait for the system to "catch up" on occasion and have needed to re-start when the system slows down to almost stalling. I did have some odd "restarts that happened without warning but have found that by adjusting the fan speeds to keep temps under control I don't experience them now. I bought the iMac because I thought it would be able to handle layered work like this better than my old one. Below are the stats for the system. Any ideas or suggestions? Any settings I should look at? I would be truly thankful for any insights.
Final Cut Pro 7
Apple iMac created in late 2009
Processor 2.8GHz Intel Core i7
Memory 16GB 1067 MHz DDR3
Graphics ATI Radeon HD 4850 512MB
Software Mac OS X Lion 10.7.4 (11E53)