Author Topic: Emulation: speed vs accuracy  (Read 7131 times)

lion_rsm (OP)

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Emulation: speed vs accuracy
« on: April 09, 2012, 09:01:00 am »
Speed and accuracy are diametrically opposite things. Emulator developers often have to choose between them. Interesting to know which parameter is more important for users.

fosamax

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Re: Emulation: speed vs accuracy
« Reply #1 on: April 09, 2012, 10:13:43 am »
I tend to prefer speed over accuracy as long as the emulating system doesn't have the needed power to achieve perfect accuracy.
When you consider the needed system to use bsnes (a snes emulator focused on accuracy), you can see that you need at least a core 2 duo running a 64bits os. Anyway, that emu achieve perfect emulation of the system.
In fact, dingoosnes gives quite a good compatibility with the fast core except for games that uses special chip (SMK, Pilotwings, Megaman X2, X3...).
That's why i perfer an emu which can achieve decent speed with little to no frameskip over an accurate emulation if it has to run slowly. I think that having both core on the dingoo with the ability to choose via a mini menu could be the way to go.
Another way to have the choice could be to rename games with .139 extension for fast core or .143 for accurate core and a way to rename games within the emu itself.
You could also make an app version of the emu in order to launch game after launching the emu.

naxeras

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Re: Emulation: speed vs accuracy
« Reply #2 on: April 09, 2012, 10:32:24 am »
Speed of course.

I'm use dingoosnes allways un speed version.

Should be great a menu with core selector between speed and acuracy.

lion_rsm (OP)

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Re: Emulation: speed vs accuracy
« Reply #3 on: April 09, 2012, 01:35:43 pm »
Vote more actively because result will affect the future of my emulators.

emrextreme

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Re: Emulation: speed vs accuracy
« Reply #4 on: April 09, 2012, 01:42:30 pm »
Speed for sure. I don't really care if the game works but in slow motion. If it works in accaptable speed that's what i call a game working.

Frank_fjs

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Re: Emulation: speed vs accuracy
« Reply #5 on: April 09, 2012, 02:24:44 pm »
Speed, especially regarding the A320 - it doesn't have the grunt to pull off accuracy in most cases. The A320 is all about playing the games, so as long as they run smoothly and mostly faithful to their real life counterpart, that's all that matters.

Surkow

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Re: Emulation: speed vs accuracy
« Reply #6 on: April 09, 2012, 03:04:23 pm »
Speed, especially regarding the A320 - it doesn't have the grunt to pull off accuracy in most cases. The A320 is all about playing the games, so as long as they run smoothly and mostly faithful to their real life counterpart, that's all that matters.
That sounds more like preferring accuracy as long as it runs full speed. I simply can't enjoy games with clear slowdowns and bad audio. I prefer to have both accuracy and speed, and otherwise I won't play the games. So this topic could be much more nuanced than simply preferring one or the other. I can live with a few graphical glitches.
« Last Edit: April 09, 2012, 03:07:04 pm by Surkow »

Frank_fjs

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Re: Emulation: speed vs accuracy
« Reply #7 on: April 09, 2012, 03:34:46 pm »
Quote
That sounds more like preferring accuracy as long as it runs full speed.

Not quite.

To gain true hardware accuracy a lot of things are done under the hood, the results of which most end users would never notice in regards to actually playing a game. In short, accuracy reduces performance significantly whilst effecting gameplay in a minimal way.

One can gain greater speed, whilst still maintaining accuracy to a good degree via clever coding, shortcuts and hacks and by not strictly following the exact behaviour of the emulated hardware. This makes the actual emulation of the hardware less accurate but games will run smoother and faster.

It's not as clear cut as saying do you want the game to run faster or more faithfully to the original - it's more about do you want the emulator to behave in an identical way to the real hardware that it is emulating, or do you want it to perform the same end result but in a more efficient yet different way.

For the sake of playing games on the A320, I think the 'speed' approach is better. If emulators were being developed for software testing and development, homebrew or hardware testing, then 'accuracy' would be more appropriate.   

Pingouin

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Re: Emulation: speed vs accuracy
« Reply #8 on: April 09, 2012, 03:36:54 pm »
Funny you're asking as I was just testing PocketSNES: albeit the fast version didn't run Super Mario Kart at all, the accurate version didn't make it quite playable enough even with frameskip=5.
So based on that, I voted "speed", and nevermind if that means a handful of games not being supported if it makes a bunch of other games more playable.

*EDIT* By "not quite playable", I mean Super Mario Kart runs just like with Snes9x4D_v20101227, so it's nothing wrong with your code, it's just the Dingoo lacking the required omf!
« Last Edit: April 09, 2012, 03:53:59 pm by Pingouin »

samir

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Re: Emulation: speed vs accuracy
« Reply #9 on: April 09, 2012, 05:52:59 pm »
Speed!!

fosamax

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Re: Emulation: speed vs accuracy
« Reply #10 on: April 09, 2012, 06:34:08 pm »
Speaking about the snes, i don't think that one core should be abandonned since all the porting has been made for both 1.39 and 1.43 and even if 1.39 usually performs better, it's not always the case (try to play pilotwings with fast core for example.).
But i guess lion want to know if he should go with picodrive, genesis plus gx or gens as a base for megadrive.
If we think about the pc engine, you could use hugo, mednafen, ootake...
A good start could be to see what have been already done on the dingoo (or dingux) and on similar handhelds (gp2x, wiz, caanoo)... or home console like the dreamcast or xbox1.
The major limitation could be the lack of a proper port of a 68000 core in mips asm (when those exist for arm cpu). I don't think megadrive needs this but if you want proper mega cd with mp3 support, it could be really usefull.

lion_rsm (OP)

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Re: Emulation: speed vs accuracy
« Reply #11 on: April 10, 2012, 08:47:17 am »
Fifteen people - is this the whole community? I need more votes!

By the way, fosamax, DingooSMD emulator is ready for 90%. But you were close in your arguments on some questions.

DiegoSLTS

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Re: Emulation: speed vs accuracy
« Reply #12 on: April 10, 2012, 11:55:07 am »
I prefer accuracy for emulators that run on PC or are ment to be ported to a lot of systems, but for the Dingoo, speed. There's no use to have a game that works but it's still unpleyable because of the speed. If that accuracy slows down the emulation of other games that worked at good fps it's even worse.

emrextreme

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Re: Emulation: speed vs accuracy
« Reply #13 on: April 10, 2012, 12:01:59 pm »

By the way, fosamax, DingooSMD emulator is ready for 90%.

Now, that's the best comment ever.

Hagane023

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Re: Emulation: speed vs accuracy
« Reply #14 on: April 10, 2012, 12:35:50 pm »
I'm voting for speed,

However i would love a snes emulator that support hi-res text for seiken densetsu 3 and treasure of the rudras. and for it to still be able to play sfa2 and megaman x 1, 2, 3.

Can't wait for SMD support. I love your emulators lion_rsm!

Many Thanks

fosamax

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Re: Emulation: speed vs accuracy
« Reply #15 on: April 10, 2012, 06:56:52 pm »
For people who want to know more about emulation in general and compatibility vs speed, you could look at http://byuu.org/articles/
Look at : The State of Emulation, pt. II http://byuu.org/articles/emulation-2/
and Emulator Optimization http://byuu.org/articles/optimization
and bsnes :: Why Accuracy Matters http://byuu.org/bsnes/accuracy

Those are well written articles that can point out the advantages of using a fast or an accurate core for an emu.
« Last Edit: April 10, 2012, 07:01:48 pm by fosamax »

maddogbr

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Re: Emulation: speed vs accuracy
« Reply #16 on: April 10, 2012, 11:05:05 pm »
Fifteen people - is this the whole community? I need more votes!

By the way, fosamax, DingooSMD emulator is ready for 90%. But you were close in your arguments on some questions.

those are great news indeed, but i wonder?
 any possibilities for sega cd emulation?
there will be a sonic cd with music?

again congrats for your great work..

raygan

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Re: Emulation: speed vs accuracy
« Reply #17 on: April 11, 2012, 05:36:32 am »
I understand that this might not be possible but I appreciate the option to toggle between fast and accurate versions of an emulator. The transparency hot-key in DingooSNES is an example of this: I love that I can leave transparency off most of the time and only turn it on when something looks funny.
That said, on portable devices like the Dingoo with limited processing capacity, I generally prefer fast over accurate, as long as most games are playable. On my computer, however, I tend to prefer accuracy.

lion_rsm (OP)

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Re: Emulation: speed vs accuracy
« Reply #18 on: April 11, 2012, 11:00:18 am »
Fifteen people - is this the whole community? I need more votes!

By the way, fosamax, DingooSMD emulator is ready for 90%. But you were close in your arguments on some questions.

those are great news indeed, but i wonder?
 any possibilities for sega cd emulation?
there will be a sonic cd with music?

again congrats for your great work..

First release of DingooSMD will not support sega cd mode. I'm not sure that makes sense to add support for sega cd, because the speed of emulation will be not high. And sega cd requires a lot of memory.

« Last Edit: April 11, 2012, 11:07:22 am by lion_rsm »

lion_rsm (OP)

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Re: Emulation: speed vs accuracy
« Reply #19 on: April 11, 2012, 11:06:31 am »
Quote
The transparency hot-key in DingooSNES is an example of this: I love that I can leave transparency off most of the time and only turn it on when something looks funny.

I agree with your opinion, this is the best approach for dingoo, if the emulation core supports the ability to switch between fast and accurate mode.

 

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