I wonder if the 3GX can run 64Mb and the 3TX can run 128Mb ... I read somewhere the TX might go up to 256mb but I've not seen anything to back that up. the TX is using a different CPU from the rest of the sparcbook line the microsparc vs the turbosparc I'm still waiting to get my 3TX from a fellow that has one.... haven't quite saved up for it yet. Chase