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Performance and Benchmark Results!

AKIKO: Did It Do Anything?

Matthew Burroughs

Posts 39
08 Jun 2018 18:38


I had a CD32 and as far as i could tell it made bugger all difference.

On my 040 1200 you see the results of the extra processing power.

Any thoughts?


Gunnar von Boehn
(Apollo Team Member)
Posts 3431
08 Jun 2018 19:10


The AMIGA used PLANAR GFX modes.
 
The PLANAR GFX modes had some advantages.
They allowed very flexible budgeting of memory bandwidth.
And allowed doing some nice tricks like EHB Effects (as seen in Bubble and Squeak) or Dual Playfield used in many excellent AMIGA games.
While PLANAR GFX worked very good for a number of Game types.
there was one type of games calles "First Person shooters" which did benefit from a different GFX memory layout. This layout is called Chunky.
 
Therefore games like DOOM were coded in Chunky and on the AMIGA then converted to PLANAR mode for display.
 
The Amiga engineers planned to add direct support both types to the AMIGA chipset. Which would have avoided the mode conversion.
This was planned for the AAA chipset - which never came to market.
 
Our current so called SAGA chipset does offer this.
SAGA does support both PLANAR and CHUNKY.
 
CD32 came out before the AAA chipset therefore converting Chunky to planar was needed. Chunky to planar is relative CPU intensive.
As the CD32 came without fastmem, the CD32 really was slow.

The best for the CD32 would have been to have AAA chipset.
The second best would have been a faster CPU e.g 030 with fastmem.
But this would have increase the cost.

Commoodre did not had the AAA chipset ready, and did not want to spend the money for fastmem or faster CPU.
Therefore Commodore did cheap patch called "AKIKO",
AKIKO offered a transpose array which helped C2P operation.
While this made money wise sense this it was not the ideal solution.
 

A system with fast CPU like the Vampire is literally 100 times faster than AKIKO.
Today AKIKO makes no sense anymore.
 


Ian Parsons

Posts 159
08 Jun 2018 20:24


Akiko was the CD interface chip it also had some IO normally handled by CIA chips on the Amiga computers. The chunky to planar functionality was something of an afterthought that allowed the marketing team to claim the CD32 had new "graphics acceleration" hardware.


Matthew Burroughs

Posts 39
08 Jun 2018 20:59


Yep, thats one of the reasons i bought one.

If that CD1200 CD-ROM was available at the same time as the CD32 (As per Commodore Uk's plan - which of course failed) i would have bought that over a CD32.




Daniel Sevo

Posts 184
09 Jun 2018 00:11


The other answers already cover most of the technical aspects of AKIKO, and to repeat the previous post, AKIKO did a lot in the CD32 but most people only think about the C2P portion of it which was actually a minor thing the AKIKO also did among other things..
  (it was a chip that replaced a bunch of other stuff found in several separate chips in the A1200 + added CD ROM controller which the A1200 did not have + the mentioned C2P).
 
  Now, other people have made fairly scientific testing of the AKIKO performance boost on a CD32 and it turns out it actually did help a bit. (I think the test were done using Gloom) and a few other games used it too. Now, as soon as you start comparing the CD32 with a 1200 with  say a slightly faster CPU + fast mem then the AKIKO advantage is no more, so it really only made a (small) difference *because* the CD32 was so damn slow. But because it was so slow, those types of games were too demanding anyway so its usefulness is marginal at best, but as Gunnar kind of mentioned: It was a cheap trick to get a small boost in performance, so why not, right?
 


Gunnar von Boehn
(Apollo Team Member)
Posts 3431
09 Jun 2018 06:58


In regards performance of Chunky modes the Vamp is optimal.

a) SAGA does support native both PLANAR and CHUNKY modes.
This means for games like Doom/Quake no software conversion is needed.

b) APOLLO 68080 does support assembly C2P and P2C instruction in HW.
If a program needs such operations, e.g. display of Amiga Icons on Chunky screen then Apollo offers best performance for this.

posts 6