Asus COP It's their Overheating protection system for Athlon based boards. It's in German but there are videos to download. In the first case, they disconnect the fan while the system is running. After a few minutes the Board shutdowns. In the second case, they remove the heatsink/fan completely while the system is running. In the last case, they power up the system withouth a heatsink fan on the CPU. Pretty interesting info, but I'm still wondering if any Athlon mainboards use the Internal Diode.