Psx4gp2x Dynarec Status Update

[zodttd]

The only thing the 940 can really offer us so far is if we can get the GPU completely on the 940. Unai has this in mind and will get that going when he's able to. Sound has been sped up a lot and the emu wont benefit from sound on the 940 as much as the demanding GPU.

 

[kevcal]

Yeah I thought that was the (long term) plan.

Is it likely that the dynarec could be sped up by more dedicated assembler?
I guess it's (mostly?) written in C at the moment.

Actually do you know where any bottlenecks are?
I seem to recall Exophase doing a profiling activity that helped gpsp out - any mileage in that?

I'm just throwing ideas in - I guess it's nothing you haven't considered already

 

[J201605]

The only thing the 940 can really offer us so far is if we can get the GPU completely on the 940. Unai has this in mind and will get that going when he's able to. Sound has been sped up a lot and the emu wont benefit from sound on the 940 as much as the demanding GPU.

If/When the GPU is completely on the 940 then what kind of performance increases would there be.

 

[___]

i think it would be quite a significant speed increase. Imagine a dedicated gpu that does all the rendering work. I would guess, zodttd cannot really give any prospective forecast of how much faster it would be, but maybe sort of a rough idea. I am also very interested. This project is getting more interesting with every post ^^

 

[yodaofborg]

Just a note, if you are going to use the 940, can you lock its clock speed to around 240Mhz? (ala Egoboo)

My 920 can clock up to 280Mhz, but if I put sound on the second core (in picodrive), and clock above 260, my 940 crashes Or maybe an option to choose the clockspeed of each core? It should be possible to clock each core independently. Just a thought, 20Mhz can make quite a difference

 

[Mudi]

To the above poster, no, both processors use the same clock speed.

 

[yodaofborg]

So how come Egoboo locks the 940 to either 240mhz or 225mhz depending on which script you run? And you can change the clock speed also?

 

[una-i]

The only thing the 940 can really offer us so far is if we can get the GPU completely on the 940. Unai has this in mind and will get that going when he's able to. Sound has been sped up a lot and the emu wont benefit from sound on the 940 as much as the demanding GPU.

If/When the GPU is completely on the 940 then what kind of performance increases would there be.


Well in previous version of the psx4ll thre was an option calldeNULL Gpu that disable renderin but mantained ther gpu managing code, and if you have the stats activated you could see the % of gp2x cpu taken by the gpu.

Its easy to compute from there, but mainly if you turn nullgpu the vsinc rate is the emulated psx cpu speed. we need to get vsinc to 60hz with sound on to achieve no sound artifacts and real speed emulation, once there movin gpu to the other cpu will help and there maybe possible to drop some frames...

P.D: I think lastest zottd builds dont have tht features activated.

 

[kevcal]

It would be reeally good to see what % the gpu uses.. even on the old builds.. anyone able to try it (don't take my gp2x to work - too distracting!) ?
I always wondered why that option was there!!

 

[fusion_power]

Because the 2. Processor can't clocked as high as the first one I would like to know what could be more effective for emulation: ONE processor used and clocked very high or TWO processors used with no or not much OC?

 

[Julius]

Because the 2. Processor can't clocked as high as the first one I would like to know what could be more effective for emulation: ONE processor used and clocked very high or TWO processors used with no or not much OC?

I guess it depends on how much use you actually get out of the second due to cache and ram access limiations. In other words it depends on the application.
But devs should also keep in mind that almost every GP2X can run both cores at 240Mhz, but only very few can go higher than 280Mhz, thus the two cpu solution should be preferred when possible.

 

[reiboul]

To the above poster, no, both processors use the same clock speed.

I think they can both work at different clockrates

 

[Mudi]

EDIT: revised: they might, but I don't think anyone has done it yet, and in my experiments I haven't found a way to do it.

 

[yodaofborg]

EDIT: revised: they might, but I don't think anyone has done it yet, and in my experiments I haven't found a way to do it.

As stated further up this thread GPU940 does this, in Egaboo... Can you not read man?

 

[fightingdreamer88]

Honestly, what can we expect AT BEST from a PSX emulator on the GP2X? I hear different stories left, right and centre and sometimes I wonder if perhaps the time of the PSX emu developers could be better spent on something that has more potential for full speed emulation. Don't get me wrong, it's very exciting watching things progress but I wonder if it's all for nothing.

 

[mth411]

I get 30fps on 2 psx games on psx4gp2x, and 20-25 on another. All 3 are 3d. So it is getting "conditionally" close for simpler games with 3d. 2D games are already there (Read about pang or strikers). Sure, I have to mess with progressive skip, and under clock the psx core to 30%, but easily done.

Emulazone: Also, how bout you work on some gp2x game, you don't need to code (there are simple games engines like fenix)... Rather than suggest someone stop what they are working on and do something for you.

BTW: the 2 30fps 3d games were Finger Flashing and Ungra Walker.

Edit: Very impressed ZOD! A little more and these games will really zip. Thanks again for the perseverance.

 

[Alex.]

Honestly, what can we expect AT BEST from a PSX emulator on the GP2X? I hear different stories left, right and centre and sometimes I wonder if perhaps the time of the PSX emu developers could be better spent on something that has more potential for full speed emulation. Don't get me wrong, it's very exciting watching things progress but I wonder if it's all for nothing.

Ooh, another bossman! :rolleyes:

 

[nubie]

Honestly, what can we expect AT BEST from a PSX emulator on the GP2X? I hear different stories left, right and centre and sometimes I wonder if perhaps the time of the PSX emu developers could be better spent on something that has more potential for full speed emulation. Don't get me wrong, it's very exciting watching things progress but I wonder if it's all for nothing.

Ooh, another bossman! :rolleyes:

Define "worth nothing", it is to test zod's personal skill.

If you want full handheld PSX emulation, get a PSP with a bad optical drive and load PSX games through the memory card slot. You can pick up a "broken" PSP on ebay for $90-140 and use it to play homebrew and emulators, at the moment it has a Sony built (and built-in) emulator for PSX, I would have to say that it is by far the best simply due to the inside information that went into building it.

This is a highly intriguing technical experiment, which I hope will come to fruition in the future on a different piece of hardware in full-speed playability with good compatibility. You notice that the front page of the website doesn't list this as news? That is to keep comments like this to a minimum, it is not intended at this time as a released program, merely work-in-progress builds.

 

[yodaofborg]

See, I do not see the current PSX emu on the gp2x as more than a tech demo, but what a fine one it is. And if Zod can get even 2 or 3 more FPS out of it I will be happy.

I got as far as rocket town in FFVII, turns out my iso is bad due to my cd being really old Had the exact same prob with home built iso's in a pc emu..

 

[Cervante]

What games are somewhat playable without sound? The most primative game that came to mind was dragon ball Z legends , the minute Gohan makes his entrace the sound goues "hu-hu-hu-hu-hu-hu" & gohan floating up and down. It even happens with sound off. FPS was between 28-31.