I better buy 16Gb for my new MacMini Server ... since the old memory doesn't work

I knew I really shouldn't be such a cheapscape all the time, but I really got enjoyment from reusing old computer components.  I call it upcycle :-P .

So my new MacMini Server has only 4Gb of memory.  I know that my replacement 8Gb for my older MacMini late 2009 model is coming, so I was wondering if I can use that 8Gb for my new MacMini Server (2012 model), and let the old MacMini to use the 4Gb (2 x 2Gb SIMM) that came with the MacMini Server.

Well, it turns out that my plan doesn't work.

My old 2009 MacMini use PC3-8500 1066 MHz modules, but the MacMini Server 2012 uses PC3-12800 1600 MHz modules.  In fact, I did tried put the PC3-12800 1600 MHz modules on MacMini late2009 model, and the machine didn't even boot up.  Instead it gave me some beep sounds.  So I swapped everything back to their own place, and both MacMini worked normally.