What is the real power of Akiko chip in cd32 ?

[LoadWB]

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

If I understand this correctly, Akiko was the C2P equivalent of the FPU?  Given that, I have a bitter taste over the Akiko.  I would have thought you could have it actually operate on a segment of memory if it was going to be a grafted-on component.  My thought was double- or triple-buffer (if the 2MB memory permitted), sick Akiko on the off-screen buffer, then switch.

Better to be integrated, as you say, in the existing custom chipset.  Very sad, indeed.

[Zac67]

If I understand this correctly, Akiko was the C2P equivalent of the FPU?

Do you mean the memory mapped mode w/ a 68000? That really is very similar. Sadly Akiko needs to be fed by the CPU and therefore somewhat thwarts the usual Amiga chip design of smart and efficient chips. But as mentioned earlier, the gate budget was very limited.

[DyLucke]

I remember playing the CD32 version of AB3D and it ran quite better than the AGA counterpart on a 020 with fast. However Akiko never was a big deal, i think it was designed more like a CD controller that could do some specific tasks aside than meant to be used for heavy processing tasks. However i always have been curious about how could
this chip had work on an A1200 with a 030 and doing C2P for Shapeshifter or PCTask.

[Crumb]

@Piru

I lack knowledge about how Akiko works but wouldn't it allow the coder to write directly to chipmem groups of 8-32 pixels without relying in a chunkybuffer? wouldn't akiko work as a small buffer that converts chunkypixels to bitplanes? something like that perhaps would allow optimizing chipmem access more. I guess that writting to a chunkybuffer and later copying to chipmem may not be as fast as writting directly to chipmem.

[NovaCoder]

- adding a chunky mode to Lisa - was missing from AGA from the start

Yep and then we could have got a chunky AGA WB

[Dr_Righteous]

Eww! I don't want chunks in it!

[Karlos]

@Piru

I lack knowledge about how Akiko works but wouldn't it allow the coder to write directly to chipmem groups of 8-32 pixels without relying in a chunkybuffer? wouldn't akiko work as a small buffer that converts chunkypixels to bitplanes? something like that perhaps would allow optimizing chipmem access more. I guess that writting to a chunkybuffer and later copying to chipmem may not be as fast as writting directly to chipmem.

One problem with the akiko c2p is that it forced you to convert 32 consecutive 8-bit pixels (8 32-bit words) into 8 32-bit planar words. That's actually fine if your application renders spans of pixels sequentially. However, a lot of the 3D engines of the day used column rendering to texture vertical surfaces. If your application needs this sort of thing, in the end, you end up having to render everything into a fast ram buffer and then doing a c2p pass over the entire buffer. Since the CPU then has to read the data back from the fast ram buffer and feed it into the akiko,, read it back and then shovel it into the bitplanes. All that shuffling can end up using almost as much CPU as a good software C2P routine. On faster processors, pure software c2p ends up being the most effective method.

[stefcep2]

It makes a small difference, but nothing spectacular.

Amiga CD32 68020/14Mhz 8Mb (Optimised 020 C2P) - 18971 realtics (3.9 fps)
Amiga CD32 68020/14Mhz 8Mb (Optimised Akiko C2P) - 12872 realtics (5.8 fps)

5.8/3.9=149% sped boost in frame rate.  People spend big dollars on a 25% frame rate improvement on modern graphics cards.  You get 50% increase in frame rate for free with Akiko. whereas a 50 mhz '030 with 32 meg ram at the time could have cost about $1800, with the ram costing about half of that.  Sure prices came down, but that was years after the CD32 was released.

[Karlos]

Amiga CD32 68020/14Mhz 8Mb (Optimised 020 C2P) - 18971 realtics (3.9 fps)
Amiga CD32 68020/14Mhz 8Mb (Optimised Akiko C2P) - 12872 realtics (5.8 fps)

5.8/3.9=149% sped boost in frame rate.  People spend big dollars on a 25% frame rate improvement on modern graphics cards.  You get 50% increase in frame rate for free with Akiko. whereas a 50 mhz '030 with 32 meg ram at the time could have cost about $1800, with the ram costing about half of that.  Sure prices came down, but that was years after the CD32 was released.

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.

[stefcep2]

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.

Yep I meant that akiko gave you a 50% increase in frame rate for essentially nothing.  And I have seen people spend hundreds of dollars on a PC graphics card to get less than 50% frame rate improvement.  And when you consider the price of fast ram, or worse still an '030 card AND fast ram at the time, you realise that akiko gave quite a bit of bang for your buck.  If Akiko was built into A1200's, it would have been used a lot more.

[blizzard-pl]

hello everybody
fortuneatly i have a SX32Pro in my CD32 and i can test adoom speed with 030 CPU and akiko
but i cant find for download ready for launch doomattack port,
i found patch files for a normal adoom, but i cant run it
message appers after load WAD file "cant create screen ",
i set stack for 20000, and i choose correct c2p file in prefs file
Cammy, can you send me ready and working version of doom attack ?
my priv : goer21@wp.pl
PS. sorry for my english
PS2. everybody know how to install 128 Meg module in SX32Pro, in instruction from DCE is written that 64 mb is maximum

[fishy_fiz]

@Blizzard-pl

First, welcome aboard
I was actually just thinking it'd be interesting to see how much akiko helps with an sx32 pro, so I look forward to seeing your results.

@thread
I seem to recall one of the gloom games having support for akiko c2p? Could be another interesting test, although is there any way to benchmark it?

[Cammy]

Hello everyone!

I have bundled DoomAttack with the better MIDI instruments file, the shareware DOOM wad, and configured it for the best settings on an A1200. Anyone is welcome to download it and give it a try, it's ready to go! If it's a little slow, run DoomAttackPrefs and disable the music by removing the text from the music plugin string, hitting Enter, and saving the prefs. I have run extensive tests on all of my Amigas and found the best results for video are the Blitter C2P (or Akiko on the CD32) and the best music plugin is the MIDI one, not the doomsound.library one. Just in case anyone was curious, here are the results I got from running the Doom Benchmark on all my Amigas:

DoomAttack

Amiga A1200 020/14Mhz 8Mb (Optimised 020 C2P) - 22976 realtics (3.3 fps)
Amiga A1200 020/14Mhz 8Mb (Blitter 020 C2P) - 20660 realtics (3.6 fps)
Amiga CD32 68020/14Mhz 8Mb (Optimised 020 C2P) - 18971 realtics (3.9 fps)
Amiga CD32 68020/14Mhz 8Mb (Akiko Optimised C2P) - 12872 realtics (5.8 fps)
Amiga A1200 030/28Mhz 64Mb (Optimised 020 C2P) - 17732 realtics (4.2 fps)
Amiga A1200 030/28Mhz 64Mb (Blitter 020 C2P) - 12727 realtics (5.8 fps)
Amiga A1200 030/50Mhz 128Mb (Optimised 020 C2P) - 8696 realtics (8.6 fps)
Amiga A1200 030/50Mhz 128Mb (Blitter 020 C2P) - 8296 realtics (9.0 fps)

ADoom

Amiga A1200 020/14Mhz 8Mb (AGA 68020 C2P) - 22984 realtics (3.2 fps)
Amiga A600 030/30Mhz 64Mb (EHB 68030 C2P) - 17886 realtics (4.2 fps)
Amiga CD32 68020/14Mhz 8Mb (AGA 68020 C2P) - 16294 realtics (4.6 fps)
Amiga A1200 030/28Mhz 64Mb (AGA 68030 C2P) - 14430 realtics (5.2 fps)
Amiga A1200 030/50Mhz 128Mb (AGA 68030 C2P) - 9133 realtics (8.2 fps)

Remember, these results are running the game in High Detail mode, in almost full-screen. The game will run faster in Low Detail mode in a smaller sized screen of course. Leaving the music on also makes a considerable performance hit so I turn it off during benchmark tests, since a PC wouldn't be using extra CPU to emulate Midi either so it's not fair on the Amiga to leave it on when testing the speed of the game engine. Anyway, here it is: Amiga Doom (DoomAttack)

[matthey]

@Cammy
Your downloaded archive contained corrupt files. Lha reported...

*** Error on file 'Midi_Instruments'  : I/O Error

I re-downloaded the archive but had the same error. It might be worth checking your archive.

DoomAttack with the timedemo (no sound) works but gave an error and no fps...

Error: timed 2134 gametics in 2420 realtics

ADoom with the timedemo (and sound) works and gives me an error but shows the fps...

Error: timed 2134 gametics in 1869 realtics ( 40.0 fps)

The closest "competitor" on the Doom benchmark list happens to be an Amiga with PPC604E-150 at 2x the clock speed and 4x the CPU cache as my lowly 68060 . The Natami 060 and fpga processors could be up to 2x as fast as me too.

[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:

[Akiko]

Wing Commander is a class game, and totally playable on the CD32!