I think it's you that has rather missed the point. The 50% it gave for an 020 won't scale upwards linearly with faster systems. Akiko gave a 50% speed increase on slow systems where the time it takes to do C2P per frame is comparable to the time it takes to do everything else, that is to say, systems which are too slow to run the game at all. Going from 3FPS to 5FPS doesn't at all imply a 15FPS game will go to 22FPS.
For an engine of a given complexity, as the CPU gets faster, the portion time it takes to do C2P on the CPU becomes less and less of the overall time of execution time until you hit the magical copyspeed bottleneck. At that point, performing C2P takes no more processor time than simply copying data from Fast RAM to Chip RAM.
Some fast 030 C2P routines are already approaching copyspeed, once you start using 040, they get there. On these systems, using an Akiko would likely result in an even slower FPS count than a copyspeed software C2P routine. The reason for that is the way Akiko works. You have to write your chunky data to it, then read back the planar result then write that to Chip RAM all using the CPU. All that copying back and forth takes longer than simply reading the source data from Fast RAM, transforming it then writing it to Chip RAM.
At copyspeed for AGA, even an infinitely fast CPU/Fast RAM combination (where the Chip RAM write speed of ~7MB/s becomes the only rate limiting factor) would be limited to around 90fps at 320x256 for 256 colours.
Doom uses a fairly simple (and efficient) 2D BSP and optimised column and span texturing routines for walls and floors and a sprite routine for objects, each of which has been pretty well-tuned. For more complex game engines, the time taken to render the frame becomes dominant and so C2P time becomes even less important. Take Quake for example. Here you have a full 3D BSP and a much more general-case textured/shaded/depth-buffered polygon rendering system. All much more CPU work than Doom. On 68K, eliminating the C2P all together (i.e. using an RTG card) only gives a comparatively small increase in fps over AGA. For 603/604 PPC systems, you see a bigger improvement because they are able to render the frame significantly faster than the 040/060 can and the whole argument about time spent rendering versus time spent C2P/copying becomes relevant again.
Simple point is nobody bought 040s to play games 68030 was a minimal improvement mhz per mhz over 020 ergo A4000/030 25mhz was slow and dead end for games.
My point is spot on thanks. So getting back on topic in relevance to A1200 and CD32 (ie 1992 and 1993) chunky screen gaming, and accepting the known fact that A1200 had to compete out of the box for less than half the price of a 386DX for £899 with monitor blah blah...... if you wanted Wolfenstein style games having Akiko in A1200 rather than not would have made a difference of 50%, and even if Commodore had the brains to use a cheaper 28mhz 020 in A4000 (which is same speed as 25mhz 030 really) OR eventually launched the A1200 28mhz 020 pizza box successor it still makes a difference at the bottom end.
We are talking games and Amigas for games use are stock A1200 + 2mb Fast Ram at best, so yes Akiko would have been usefull (as would have IDE connector and Fast Ram SIMM slot on CD32 motherboard).
If anyone had programmed 030 games worth a sh1t then I might be swayed but fact is 90% of AGA games are badly programmed mildly breathed over crap.
Or Akiko on A1200 AND proper programming would have made games on Amiga 1200 for 99% of people expecting to play better games than a 1985 A1000 a bit less 'old' looking in 93/94.I fail to see how £3000 A4000 with 040 50mhz and 16mb Ram performs playing Doom engines compared to £1500 PC running them the same speed is remotely relevant and yet more thread dilution and off topic dreaming. WHO CARES? It's like saying a Mercedes 6L V12 pissed all over a Ford Fiesta 1.6L straight 4 engine....true but bollox that is not helpful
