DDR-SDRAM is DDR-RAM!!!
The more correct name for DDR-RAM is DDR-SDRAM!!!
but it's too long and takes more space!!! so... it's shortened
but MB which supports DDR doesnt usually support the normal SDRAM, and if it does it usually has separate slots for the DDR and the normal SDRAM.
u can check the MB manual for that.. which should also be available for download.
brand-new modules of the normal SDRAM cost more than the DDR-SDRAM with the same density (capacity or MBs).. just introducing the term density
umm does your MB installation CD come with a program with the word "DMI" in it, then it's the tool to view things like type of RAM... etc... you can do it with other programs like the one u used but the DMI thing is one option.