Flash951 wrote:I'm aware a good programmer can get some additional speed by taking use of the DSP, but the real life speed increase compared to just using the 030 instead is not that extreme that some Atari ST fanatics claims it is. And when the DSP are being used, it has some down sides, like slowing the RAM bus ore something else down, so other stuff that might are running at the same time will suffer. That's my understanding after reading what I can here and there. I have not had an F030 to experience with myself, I've just have a normal Atari ST.
The DSP does not slow down the CPU. It has its own separate RAM. There is another advantage of the ST/Falcon architecture. The data cache can work with ST (Chip) RAM. On the Amiga chip RAM access is only cached via the instruction cache. The ST has a clearly defined interface to bitblit which takes care of flushing the data cache on every graphics operation. Remember that the Falcon has a 16 mhz 16 bit bus to ST ram. The 1200 has a 7 mhz 32 bit chip RAM bus for the CPU. That's why fast ram gives you such an increase in speed on the 1200. As an aside the 030 on the Falcon has an MMU too.
The Falcon blitter can also gourad shade via x increment registers and true colour mode which the Amiga blitter lacks. Details here... Enjoy http://s390174849.online.de/ray.tscc.de/gouraud.htm