I have a Celeron 700 adn 256 MBs of RAM. My M2 .cr2 is an easy 90MBs, and I know off hand my P4NW has around 1500MTs. These both load, save, and render fine in P4 and P5. It just takes a minute, almost exactly. I noticed this yesturday. I have my screen saver set to 1min, and each time I loaded, or saved, my HD light would stop going on just as my screen saver cam on. My renders on this 1600x1200 screen are about that too!