I have P3 1Ghz with a memory of 512mb sdram PC100(256mb sdram PC100). There's 1 slot left and Im planning to upgrade it to 1Gb by adding another 512mb sdram. The only problem is Im having a hard time to find PC100 but instead PC133. I want to make it 1Gb memory is it possible to add 512mb sdram with a different frequency? Could this be work? Need your help. Thanks!