Emulator Issues #13254


Skies of Arcadia Legends audio issue with LLE

Added by ichee1 22 days ago. Updated 19 days ago.

% Done:


Operating system:
Issue type:
Relates to usability:
Relates to performance:
Relates to maintainability:
Regression start:
Fixed in:


Game Name?

Skies of Arcadia Legends

Game ID? (right click the game in the game list, Properties, Info tab)


MD5 Hash? (right click the game in the game list, Properties, Verify tab, Verify Integrity button)


What's the problem? Describe what went wrong.

When using LLE Recompiler with a dumped DSP, framerate fluctuates wildly with garbled audio. Issue does not occur with included DSP.

What steps will reproduce the problem?

Using a dumped DSP, set audio to DSP Recompiler. Load game and save from provided memory card below, and observe audio and framerate on world map.

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.

Yes. 5.0-19363

Is the issue present in the latest stable version?

No. 5.0

If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool and anyone who is building Dolphin on their own can use git bisect.)

5.0-14988 (this build broke audio playback so it is difficult to observe, but framerate still fluctuates)

What are your PC specifications? (CPU, GPU, Operating System, more)

Windows 11
Intel 10900X OC @ 5Ghz
Nvidia RTX 3090
Intel Nvme P5800X

Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)

DSP dumps:

dsp_coef md5: 9A6514B88003C9C47E334DE654EC550B
dsp_rom md5: 23645D446729A166AB3A9AABA2F5FBA5

Audio samples, memory card, and fifo log attached below.


skies_audio-2.ac3 (81.5 KB) skies_audio-2.ac3 audio from build 5.0-14976 (build before issue started) ichee1, 05/10/2023 08:15 AM
skies_audio.ac3 (82.5 KB) skies_audio.ac3 broken audio ichee1, 05/10/2023 08:15 AM (336 KB) save on world map ichee1, 05/10/2023 08:22 AM (2.97 MB) fifo log (unlikely to show anything since not graphic issue) ichee1, 05/10/2023 08:41 AM
Actions #1

Updated by JosJuice 22 days ago

  • Relates to performance changed from No to Yes
Actions #2

Updated by pokechu22 21 days ago

Can you check 5.0-14993 (which fixed a regression from 5.0-14988)?

Additionally, does this issue only affect the DSP LLE recompiler, or does it also affect the DSP LLE interpreter?

Actions #3

Updated by ichee1 20 days ago

5.0-14993 only fixed no audio caused by 5.0-14988. Performance problem still remains.

Only DSP LLE Recompiler is affected, and only when using dumped DSP's. The included reversed engineered ones are unaffected.

DSP LLE Interpreter has the same performance both before build 5.0-14988 and after.

Actions #4

Updated by pokechu22 20 days ago

  • Regression changed from No to Yes
  • Regression start set to 5.0-14988

OK, that's good to have confirmed.

Can you check if this is a dolphin performance regression, or a difference in emulation behavior? The easiest ways to check would be to enable "Show FPS" and "Show VPS" under graphics -> advanced, or to enable Movie -> Dump Audio and then look at the file generated in Dolphin's Dump/Audio folder (make sure to turn "Dump Audio" off afterwards, or else you'll end up with gigabytes of audio data later without realizing it).

It'd also be helpful to check which commit in PR 10045 (i.e. from this list) caused it, if you have the ability to build Dolphin yourself. (You'd use e.g. git switch -d 779cd479bc7ddcaaa3826f54146ee6aef22310ee to switch to the last commit.) I don't have a copy of Skies of Arcadia Legends and it seems to be rather expensive, so being able to drill down into exactly when it started would be very helpful for making a build you can test. If not, that's fine; I can try to figure it out another way.

Actions #5

Updated by ichee1 20 days ago

Both FPS and VPS dip below full speed, if that's what you mean.

I've narrowed it down to commit 105d886

Reverting that one commit restores performance.

Actions #6

Updated by pokechu22 19 days ago

Huh. Commit 105d886 is a performance-accuracy trade off (disabling an optimization that was incorrect in some cases, though I don't remember whether it affected games or only some of the specialized tests I wrote). I can look into restoring that optimisation.

Just to clarify a bit more: did this cause the recompiler's performance to be worse than the interpreter? It'd be helpful if you could get performance values for the recompiler and interpreter both with and without the change and both with and without the dumped DSP ROMs, that'd be nice (but that is 8 combinations so it might be a bit annoying).

Actions #7

Updated by ichee1 19 days ago

Recompiler is still faster than interpreter, though not by much on master.

Performance between each is as follows (bare with me if this is too unorganized):

Master with dumped DSP - recompiler: 26 FPS 50 VPS

Master with included DSP - recompiler: 37 FPS 75 VPS

Reverted commit with dumped DSP - recompiler: 36 FPS 75 VPS

Reverted commit with included DSP - recompiler: 44 FPS 90 VPS

Interpreter maintained roughly 20 FPS and 40 VPS in all examples with both builds.

Just for comparisons sake, though probably unnecessary, HLE for both builds is: 115 FPS 233 VPS.

I should note that while getting these performance numbers, I decided to check out some other games as well.
Most of them on Master maintained a FPS of over 70 and a VPS over 140 using the lle recompiler with dumped dsp's.
I'm not sure why Skies of Arcadia Legends is hit so much harder than the rest.


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