After installing/upgrading ram for a mac, compatibility issue could occur. So what is the best way to test the new stick is fully compatible with your machine rather than using the Hardware Diag CD(sometimes this just don't work)? Some suggested open up photoshop and do some work on BIG files such as files larger than 100mb, and see if the machine is still alive after the task...... This is really a simple way, if this works as expected. what's your solutions?