>>106566061
If we measure "weakest" based on processing speed, DSi has 133 MHz ARM9 + 33 MHz ARM7 = 166 MHz total, whereas my communicator >>106571373 is 150 MHz ARM925T, so I win assuming equal speed.
However, DSi only has 16MB ram, while the communicator has whopping 64mb, out of which 20mb is available for programs.