Re: [hatari-devel] relative perf between 030 / DSP / CPU?

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 24.6.2025 12.39, Nicolas Pomarède wrote:
> No, 040/060 is not cycle accurate at all and will likely never be 
> (seeing how difficult it is to get CE mode on 68020/30 without any 
> available doc of the inner working of the cpu, there's no chance we will 
> ever have it on 040/060)
>
> For now, IIRC all 040/060 instructions are considered as taking 1 cpu 
> cycle, which gives the expected speed boost compared to 020/030 but is 
> of course not accurate at all.

Ok, that's good to know!

Btw. Have you planned any improvements to the FPU emulation accuracy?

Centurbo Bench reports following numbers for emulated 16Mhz Falcon with 
Hatari Git version, in 640x400@2-bit and 640x4@16-bit Falcon resolutions 
(under EmuTOS v1.4).

With no MMU:
CPU: 96-119 Mhz
DSP: 60-63 MHZ
FPU: 588-796 Mhz

With MMU:
CPU: 112-116 Mhz
DSP: 63-65 MHZ
FPU: 269-275 Mhz

(Lowest numbers are when moving mouse, and both CPU & FPU numbers 
fluctuate a lot more without MMU.)

For some reason it reports DSP running at nearly half of the CPU speed, 
instead of the expected 2x speed (32Mhz DSP vs 16Mhz CPU). And there's 
the rather radical 2x-3x FPU speed difference caused by MMU.

Any idea why these might happen?


	- Eero