Last week I bought duron600 from buy.com. When I test the float performance I find duron600 is 10% slower than classic Athlon500(running a program, duron600:1177s, Athlon500:1068s). This means duron is 27% slower than the Athlon at same frequency. How odd! Because many reviews said that FPU of duron is same as Tbird. How come there is 27% gap between them.