I have a spare Optiplex that was given to me by a relative. Was looking it over and was wondering what parts could I use from the Optiplex into a Dimension B110.  

Notice, the Power supplies are the same.  I need to replace the one in the Dimension anway.

How about the Dvd/cd rewritable Drive and the 250 gig hard drive both from the Optiplex.

Also, the Optiplex has 3gig ddr 2 memory and Intel Pentium 4 3.0g.  Read, the memory are different from the Dimension and the socket are also different.  

I read, that the ddr2 is slower than the DDR3 which is in my Dimension is this true.