Re: [hatari-devel] rev 3689 : splitting cpu cycles above 20

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On sunnuntai 08 tammikuu 2012, Anders Eriksson wrote:
> The timings that are of most importance are CPU:DSP, many demos rely on
> the ratio to be 1:2 and have the correct speed (also need memory
> bandwidth simulation to be solid). Eg, a normal CPU-loop can be:
> move.w (a0),(a1)+
> Where a0 is the host port and a1 ST-RAM. The speed on the ST-RAM access
> greatly differs between resolutions used.

Because Videl transfers from video RAM to VGA/RGB at 50/60Hz in
the "background" take part of the RAM access memory bandwidth?
Does it correlate directly to Width x Height x Bitdepth data amount?

Do you have numbers on how much this effect is at its smallest
and largest?

> If the emulator doesn't take
> ST-RAM bandwidth into account, demos will crash because of the too fast
> CPU loop.

I don't think that's taken at all into account in Hatari...


	- Eero

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