Old machine: Mid-2009 Core 2 Duo (C2D from now on) New machine: Late-2011 i7 (i7 from now on) I've just upgraded from the C2D to the i7. The C2D had two 1Tb hard drives, and we've swapped these into the i7 as I was told OSX would automatically sort itself out with regard to any different drivers, etc, it needed. The good news: the i7 starts up, runs everything and once apps are open, it is lightning-fast. The bad news: apps take an age to load in the first place. As in 15-20 seconds with spinning beach-balls for apps that loaded in 2-3 seconds on the C2D. Opening folders for the first time also takes several seconds. I've done PRAM and SMC resets. Any ideas what the problem might be? It's not a disaster if the straight drive swap we've done isn't a viable method as I can do a clean install of Lion then use the migration assistant to restore from Time Machine, but as there's a little over a terrabyte of data to restore, I thought it would be worth a little more investigation first.