32bit is not always better than 16 bitEvilFranky wrote:It would have been nice I admit if it was running with a full 32-bit BUS
A good example is Amiga 1200. It has 32bit bus, but CPU has very slow access to it - every 8th clock, in case of Falcon it is 16bit bus with 4th clock CPU access. Due to Falcon's main clock - 16Mhz (vs 14Mhz in A1200) bus performance should be 12% better.
But there is something else - size of manipulated data vs memory size/access time. Lets try to read e.g. 10 Longwords/Words/Bytes from memory:
* A1200 32bit bus, 8 cycles per access:
- 10 Long words - 10 memory cycles - 80 CPU cycles;
- 10 Words - 10 memory cycles - 80 CPU cycles;
- 10 Bytes - 10 memory cycles - 80 CPU cycles;
* Falcon 16bit bus 4 cycles per access:
- 10 Long words - 20 memory cycles - 80 CPU cycles;
- 10 Words - 10 memory cycles - 40 CPU cycles;
- 10 Bytes - 10 memory cycles - 40 CPU cycles;
Now lets try to set one pixel on the screen in 8 bit plane mode:
- A1200 line organization - 1 memory access per plane x8 planes x8 cycles per access = 64 CPU cycles;
- Falcon interleave planar organization - 1 memory access per plane x8 planes x4 cycles per access = 32 CPU cycles;
In this case Falcon should be more than twice faster than A1200.
Of course there are only my theoretical reflections
