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Old 15 May 2012, 11:42   #14
kamelito
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Quote:
Originally Posted by niobyte View Post
I would safely say these are definitely Amiga version screenshots. These would have been from the CD32 version (first screenshot is most likely from an earlier build).

The framerate would have been possibly anything from 1 to 16 frames per second (being over generous) by the looks of it. I would think around 4 to 5 frames per second would be 'realistic'.

Would be interesting how they would have utilised this (especially if using bitplanes on the A1200 version [planar only version] or eventually making the game for an accelerated Amiga utilising a C2P routine). I think a CD32 68020 14MHz with the akiko chip is asking a bit.

I don't think the Akiko chip would be fast enough to handle this kind of level of detail (as in yes it is possible but expect a 'dull' framerate). In fact an optimised C2P routine on the CPU [talking non- 68020 14 MHz now. Akiko is still faster than an optimised C2P routine at this clock speed] will still most likely be faster than relying on the Akiko chip (as there is a limited bandwidth also not being able to utilise fast RAM - chip RAM is slow).

Akiko chip = Writes the chunky display words (4 bytes each) to its own registers, then read back and copy the planar converted data (as Akiko has been explained as only being able to read/write at copy speed). At least with a software implementation you can change this approach using a trick known as write pipelining (allowing for the write buffer to commit memory writes while the other instructions are being executed in different stages part of the pipeline)

In this case no matter the speed of the CPU the Akiko chip becomes the 'bottleneck' in the end. Still if you only have a 68020 at 14 MHz the akiko is the 'faster' option. At the time accelerators were expensive so this was the only option for most.

I can see why it most likely didn't go past the concept stage as the speed wouldn't be feasible for most. Still if the amount of detail was dropped further would have had a bit of improvement in speed (e.g. draw distance, smaller even simpler textures, small screen dimension size, etc).
I suppose that lowering the horizontal and vertical resolutions, then doubling the vertical one using the copper like on Unreal would help to increase the framerate.
Is Akiko capable of writing in less bitplanes (ie not 8) then be faster doing it?
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