I mounted 2 133 SDRAM 512MB modules on an MSI 6199 motherboard VIA. Compatibility is only partial. Explanation: The MSI motherboard only recognizes 512MB modules comprising memory modules on the front and on the back thus constituting 2x256 MB (read documentation MSI ATX V93T.pdf 6199VA). But here, the memory modules are on one side of the bar which is not specified in the datasheet section. Consequence: only 256 MB to 512 MB will be recognized in each of the strips.