If the Zorro II slot operates at 7.16 MHz and it is a 16 bit bus (16bit = 2 byte) then its transfer speed should really be 14.32 MByte/s.
That would be true if only there were not four clocks per bus cycle (Amiga Hardware Reference Manual, Page 391). There doesnt seem to be a burst mode and so 1 bus cycle is 16-bits. This is where the 3.58Mbyte/s value that is quoted in lots of places comes from.
(Note that Zorro II is a CPU clock synchronous bus and so PAL systems are 7.09MHz or 3.54Mbyte/s)
And if the Zorro III bus operates at 25MHz and it is a 32 bit bus (32bit = 4 byte) then its real transfer speed should be 100 MByte/s.
Zorro III is a totally asynchronous bus and so "25MHz*32-bit" is meaningless. The maximum speed of the Zorro III bus is determined by the setup-and-hold times of strobe signals going to the BUSTER. These are discussed in the HRM but I am not going to quote/prove them here.
