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Old 17 August 2015, 10:06   #16
kovacm
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Join Date: Jan 2012
Location: Serbia
Posts: 269
Quote:
Originally Posted by SKOLMAN_MWS View Post
68040 30MHz 21,68 MIPS 7,23 MFLOPS link

DSP in Falcon in reality faster than 68040.
It is really complicated; I am not sure what instructions Motorola take into account when declare DSP as 16MIPS (e.g. multiplication are really fast but bit-wise operation are really slow on DSP). You also need to remember that DSP has only 96KB of memory (!) and access to main memory is only 8bit wide so you need very carefully how to "craft" 3D engine!

There are really lot of details at atari-forum; there are diagrams with chunk of codes and how they are managed between CPU and DSP...

MC 68040 (and espec. 060) are quite different than 68030 founded in Falcon. In many cases, using solo 040 would perform faster than 030+DSP. This engine is specially crafted for stock Falcon (beside DSP, using MC68030 256bytes cache, MMU...) and would not benefit from e.g. 040 or 060 CPU as it could.

Quote:
Originally Posted by beezle View Post
Floating point is also a lot more precise than interger, something that at times is important, especially when it comes to 3d.
Ofcourse. DSP in Falcon have 24bit words and as you saw, Doug manage to implement 3D engine that will work well with given precision.

Last edited by kovacm; 17 August 2015 at 10:12.
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