This is a design for a ripple carry adder that can do the carry for 8 bits instantly, allowing for fast addition.

I've included designs for 5 different sizes in the world save.

Speed (1 tick = 0.1 sec)
4-bit: 5 ticks
8-bit: 6 ticks
16-bit: 8 ticks
32-bit: 10 ticks
64-bit: 14 ticks.

Size
2x17x6 per bit

This is mostly focused on making the adder scale well, for the smaller adders it could be possible to sacrifice size for even more speed.

Thanks to cooperation with Hans Lemurson for helping with the 2 wide design:
www.youtube.com/user/HansLemurson.