What is the real power of Akiko chip in cd32 ?

[Digiman]

I think that would be an excellent test.We have to remember that back in that area the game production was moving toward chunky style with 256 colors.
I can't understand some of Commodore's desicion's.Use a chunky to planar convertor while not giving any fast ram at all.
I think there is wing commander cd32 that uses akiko.What is the speed of it?
I know there is a special patch for accelerated amigas with fast ram for that game.
But back in the cd32 area with only 2mbytes did wing commander cd32 play the same speed as a fast equiped pc?

Forget it even exists, one of the worst bits of coding ever seen. Barely improved over crappy A500 version. Luckily the game is c0ck anyway :roflmao:

[Digiman]

It makes a small difference, but nothing spectacular.

Also, when the actual game gets more complicated the amount of time spent on c2p conversion lets smaller and smaller, and so does the performance boost given by Akiko.

In short: Having akiko on existing A1200 systems would give no benefit whatsoever, except maybe in case of an 030 accelerator. If your system doesn't have an accelerator it is really too slow to run the game anyway. If your system does have an 040/060 accelerator it's as fast to use optimized c2p (they reach copyspeed) anyway.

You miss the point, big deal a 486 33mhz requiring game requires an 040 25mhz Amiga shocker.

The benchmarks show a 50% speed improvement. So if you wrote any game engine and it managed 13-15fps on A1200 sans Akiko you can make it run 22fps for free on Akiko. The issue is 95% of Amiga games had sloppy n00b coding.

Both A1200 and CD32 should have had a single SIMM slot to add fast ram AND Akiko.

040 50mhz card = £799 in 1992 so stop going off topic.

[Digiman]

Given the very simple way Akiko works (write chunky words to its registers and then read back/copy the planar converted data) it's no surprise the speed up is rather moderate. AFAIR there was some space left on the gate array that was to become Akiko and the developers tried to think up something useful. Well, they did, given the budget.

Something that would really have made a change:
- adding a c2p converter in front of Lisa's bus interface with on-the-fly conversion - no waste of bandwidth here
or better:
- adding a chunky mode to Lisa - was missing from AGA from the start

OR just scrap Amiga compatibility and make it all 8/16/24bit chunky pixel modes only (as compatibility is the whole reason AGA was a luke warm minor upgrade...2 years too late). Chunky AND planer doesn't mix and is hugely epensive....ie AAA chipset trainwreck.

[Digiman]

Most people that have graphics cards aren't using them on a 68020 so your comparison isn't valid. The speed up for my 040 on an RTG card over AGA was immediately obvious.

-edit-

Oh wait, you are referring to modern cards on other systems, not RTG versus AGA. Yeah, you have a point. I currently have a GTX260, hopefully I won't get any newer card that isn't at least 50% faster.

Think the point is you get something for nothing, in 1992 a SIMM slot for A1200 fast ram and Akiko would have helped sales against £999 386DX 25/33mhz PCs.

Commodore didn't go bankrupt because nobody wrote Doom style games for Retina or Picasso graphics card equipped 33mhz 040s you know

A1200 was not thought out properly, a SIMM slot costing 50 pence would have allowed users to easily double the speed of the new fashionable Doom style crap popping up everywhere and if Akiko was on the motherboard too thats 50% for Akiko and 100% for CPU speed increase for the price of a 512kb SIMM purchase compared to what we were stuck with. And luckily for us because Amiga games were so badly programmed most of that increase in speed is automatic.

A1200 had no Akiko option and bare FAST RAM cards alone were £125 with no memory included for A1200s and CD32 was an 'unexpandable toy' unless you spent another £300 on an SX32 type device. £650 for a 14mhz computer vs £999 for a 40mhz one with monitor and 16bit sound card from Win/Tel world.

Commercial suicide. Can you imagine Sega or Nintendo or Sony getting themselves in that situation? Exactly.

Sad thing is the A1400 (A1200 with CD drive and 28mhz 020 and 2mb Fast Ram in A3000 style 3 piece case design was nearly ready for 3rd quarter 94).

[Digiman]

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