> Your motherboard will either support 100 mhz or 133 mhz chips but not both. His motherboard is showing 384MB so its reading both 133 and 100. Quoting: Mixing PC100 and PC133 memory: PC100 and PC133 memory usually can be used in the same machine, but memory will typically run at the speed of the slower modules. Not all machines accept modules of different speeds. Sometimes updating the system's BIOS corrects this, but if not, it is usually best to use only the speed specified by the motherboard manufacturer. http://home.att.net/~gallgosp/comphard.htm