DDR1 vs. DDR2

[Flip81]

I understand the differences for the most part.  That is, DDR2 uses a 4-bit prefetch versus DDR1's 2.  Data rate begins at 400-667 for DDR2 versus DDR1 ends at 400, and etc, etc...

my questions is:  Is there a definitive VISIBLE difference in the two?  Is there a hole or notch in the side or on the pins that makes it easy to differentiate?

thanks!

[quaxo]

DDR is 184 pins. DDR2 is 240 pins. Each has a single notch, but it's located in a different place on each type.

Wikipedia has a page for each type, including descriptions of the physical differences.
http://en.wikipedia.org/wiki/DDR_SDRAM
http://en.wikipedia.org/wiki/DDR2