I got an iMac, purchased in 2010, and I have noticed that it's performance has been getting slower as time goes on. A few months ago I increased the Memory from 4 GB to 12 GB, but it doesn't seem to be improving. When downloading movie trailers from Apple, it used to be super fast, now it takes even longer, youtube videos take longer to load and sometimes a video doesn't even show up but audio does. I get the spinning beach ball every once in a while, and it's annoying. Currently, my Processor is: 3.06 GHz Intel Core 2 Duo, and my Memory is: 12 GB 1067 MHz DDR3. Would I have to increase my Processor to make it faster? But if that's the case, isn't it really hard to DIY?