My g5 seems to be fast but at the same time every now and then it acts like its not fast, for example when im playing WC3 it will load fast but take a long time to regester on the screen. some times there will just be a lot of lag like the computer does not want to go anymore. Im assuming this is due to the 512 ram. Im only running aim and one DL in the back ground but thats all i can think of.