Homebrew
This post it's pretty much a repeat of the info found after searching for a while condensed here with some stuff I've found through testing while sorting my library, don't expect the settings to run flawlessly on everything at once but test around and see what fits 
The version I'm using is one of the latest 1.16 retroarch slable (05/11/2023). This settings should work on any build 1.15 or higher.
Most Retroarch versions in 3DS tend to freeze the console when switching settings on or off (Threaded VIdeo)
If that happens just find your retroarch.cfg file and use a notepad to change the config setting you want.
(In the latest 1.16 nightlies (October and newer) Threaded Video freezes the console when loading certain games but it seems that the newer versions fixed some if not all the FMV stuttering that happened before in 1.15 so there's no need to turn it On anymore)
(OUTDATED)
Inside the main retroarch settings, the main FPS helpers are Threaded Video and obviously audio. You can play most games without TV on but it really helps with the lag in FMV heavy games, I've tried around 20 games now on my N2DSXL and every game stutters a bit with TV on or off, I'd recommend this for older stable versions as the 1.16 update seems to have broken this setting, freezing the console when loading so it's a hit or miss.
If you have a New DS with Luma, run the payload at boot and make sure that you have the Clock+L2 option checked, later make sure you have it On inside retroarch (power management settings).
In the list below check the 3rd option:
Redirect app .syscore threads to core2 (As it reads, It might break some other 3ds games but retroarch does work and all of the games & apps I have work no problem, idk about homebrew as I don't have much installed and haven't tested)
After that just save the settings and boot Retroarch.
Go straight to Video settings, set Bilinear Filter Off and try a Video filter instead. I personally like the smoothness of bilinear but it does slow down the games.
(The filters are completely optional, just use them if the image feels too sharp after setting a different aspect ratio).
Leave audio at dsp or dsp_thread (I haven't seen any differences from either or really) and turn audio sync On (might want it off depending of the game as it can uncap framerate, this DOES slow down games if on).
As for the format of games you can use BIN files for retroachievments or CHD files which do take less space but no Achievments :c
CHD are superior though as they take less space and you can set the psx clock speed to speed up games and that could help a bit in some cases, they also load faster as they don't get checked by cheevos on retroarch (achievments).
In Quick Menu when running a game, All the Threaded options shoud be on if not auto (Threaded Rendering and SPU). Frame Duping should be On aswell (in Tekken 3.chd the game runs smoother with Threaded Rendering on Sync so either Sync or Async try with each game).
Dynamic Recompiler it's On by default and should always be as it does help with framerate.
In gpu plugin settings turning On Hi-Res Downscaling increases fps most of the time but it does break some games, Fast Lighting is ok but doesn't really impact performance but Disabling Lighting Effects does make Tekken 3 go from 27 fps to 30 (no shadows or particles though).
Disabling Blending will make you game look worse (effects and particles) with no changes in performance so best leave it On.
The video quality is bad because my phone and recording skills aren't the best :v
(these videos are from an older version with Threaded Video On, 1.16 builds don't need it anymore).
If you want to test Tekken 3 exclusively fight Yoshimitsu in Practice mode (Forest Stage) and tinker with the settings there, that stage has the most slowdown and should be a good way to see if the changes make a difference.
(Tekken 3 and Soul Blade are the only games I found that run better without audio sync at the moment, when testing make sure audio sync is On to check if the game uncaps or not, then turn it Off to see if it runs better or only speeds up).
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CORE OPTIONS (1.16 and newer nightlies)
Threaded Video: Off
Dynamic Recompiler: On
PSX CPU Clock Speed: 64
Frame Duping: On
Threaded Rendering: Async most of the time, some games prefer Sync
Frameskip: Off (user preference)
Texture Blending: On
Lighting Effects: On
Fast Lighting: On
Hi-Res Downscaling: On (Off if you want more performance, can break graphics sometimes)
XA Decoding: On
Threaded SPU: On
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Tekken 3 with V-sync and audio sync Off, Threaded Video On and Threaded Rendering set as Synchronous,
psx clock speed 55 (at higher values it does make the gameplay and some cutscenes run better but the opening cutscene, menu and the credits speed up quite a bit, I've also tested at 70 and it runs smoothly with some slowdowns depending on the stage).
N-Zero and Final Fantasy 7 tested with the same settings but with audio sync On and the cpu clock set at 80.
Gran Turismo 2 tested with the same settings as above but without audio sync (having it On only fixes the clicking, no performance increase or decrease in this one).
These settings work well for Gran Turismo 2 as tried a few races on maps I knew there was big slowdowns when crossing areas with lots of scenery (trees or houses) and now barely has any slowdown.
For some reason the cars sometimes don't display properly on preview without turning Hi-Res Downscaling On, the menu and font look worse with it but it runs better and it doesn't happen in races so yeah.
I recommend using the Duckstation cheats as you can enable Higher Draw Distance without any performance drops as far as I know so check it out (google: libretro gt2 .cht)
The Final Fantasy main games run well on overworld with a bit of slowdown when in a battle, IX slows down more that VII but it's not much of a difference, I haven't tested VIII yet but the performance should be around the same.
Azure Dreams runs great, played up to the 12th Floor.
Bushido Blade 1 runs pretty much flawlessly, the loading times are not great though.
Diablo runs flawlessly, no issues as far as I know.
Dr. Slump isn't a demanding game and runs flawlessly with this settings.
Metal Gear Solid runs at a steady 30 (at least on the first stage as I haven't played past it).
Persona 1 runs great with this settings, the first FMV was laggy the last time I tried but not anymore.
N-Gen Racing doesn't quite stay at 30 fps but it doesn't slow down much either so it's 99% playable.
Soul Blade runs great with minimal slowdown but performance drops a bit when fighting Soul Edge at stage 11.
Tony Hawk 3 runs great, finally a good skate game for 3ds.
The Tomb Raider games run well with these settings, having the same issue as FF7, but for some reason playing it at uncapped speed feels smoother (atleast on TR1). TR2 runs a tad bit slower than 1 and same with 3 but it's still playable, this is normal as they're games that use the same engine but add more with each sequent title.
The Tenchu games behave similarly to Tomb Raider, they run well capped, but it feels smoother leaving audio sync off as they're slow games in the first place, uncapping them makes the games run at fake 40FPS as they're sped up.
All the games tested are NTSC, I'm not too sure but they might benefit more than PAL ones from the clock speed increase as they have more frames to show per second, I might be completely wrong but yh NTSC better anyways.
Having audio sync On can make a difference for games that already run well enough as it fixes the clicking when audio is playing and some games need it for the FMVs/cutscenes to play properly.
The other speed hack options differ a lot inbetween games but on most games I did not find any notable differences.
------------------------------------------------------------------------------------------------------------------------------------------------------------------
Now again the psx clock:
In PCSX the psx default clock speed is 57, but if the game is in BIN format even if you can change the value it won't do anything, if the rom is CHD the value does apply, so whenever you set it past 80 (as I've tested) most games running with audio sync Off are going to have their framerate uncapped and could even black screen, flicker or break in some other way but games also uncap at default clock speed values with this change if you're playing CHD so it's better to turn audio sync On so they run at normal speed.
Turning audio sync On will cap your framerate and reduce performance slightly which is important but most games benefit from having a high cpu clock speed value and turning audio sync On (Final Fantasy 7 uncaps without it but runs well with audio sync On (Tekken 3 loses performance with it but the smoothness improves quite a lot with the setting Off).
Here's an example with Tenchu 1 with the settings above (core options):
With Audio Sync
Without Audio Sync
As you can see the game speeds up nicely but the audio clicks more which isn't really great.
Most games will run fine as long as the clock is around 64 - 80, but some speed up by around x1.25 - x1.5 if audio sync is Off so test around and see what fits your game, personally I've seen that a clock speed above 64 with audio sync On helps improve performace on most titles but games like Tekken 3 don't like getting their framerate capped and run slower if audio sync is On, (the music syncs and sounds good but it takes a hit in performance).
Turning it off makes the game jump up to "fake" 40 - 45 FPS so again, test around and see what fits.
Depending on the game disabling the Lighting Effects might not be a bad idea, It will for sure look worse but all games run better without them no exceptions (as far as I know).
(OUTDATED)
(Having audio sync on + Threaded Video should fix cutscene and audio clicking related issues with any game).
Make sure to reload the core when changing the clock speed as it might not set while running the game.
This is not all, I'll keep adding more stuff as I find but this is it for now
The version I'm using is one of the latest 1.16 retroarch slable (05/11/2023). This settings should work on any build 1.15 or higher.
Most Retroarch versions in 3DS tend to freeze the console when switching settings on or off (Threaded VIdeo)
If that happens just find your retroarch.cfg file and use a notepad to change the config setting you want.
(In the latest 1.16 nightlies (October and newer) Threaded Video freezes the console when loading certain games but it seems that the newer versions fixed some if not all the FMV stuttering that happened before in 1.15 so there's no need to turn it On anymore)
(OUTDATED)
If you have a New DS with Luma, run the payload at boot and make sure that you have the Clock+L2 option checked, later make sure you have it On inside retroarch (power management settings).
In the list below check the 3rd option:
Redirect app .syscore threads to core2 (As it reads, It might break some other 3ds games but retroarch does work and all of the games & apps I have work no problem, idk about homebrew as I don't have much installed and haven't tested)
After that just save the settings and boot Retroarch.
Go straight to Video settings, set Bilinear Filter Off and try a Video filter instead. I personally like the smoothness of bilinear but it does slow down the games.
(The filters are completely optional, just use them if the image feels too sharp after setting a different aspect ratio).
Leave audio at dsp or dsp_thread (I haven't seen any differences from either or really) and turn audio sync On (might want it off depending of the game as it can uncap framerate, this DOES slow down games if on).
As for the format of games you can use BIN files for retroachievments or CHD files which do take less space but no Achievments :c
CHD are superior though as they take less space and you can set the psx clock speed to speed up games and that could help a bit in some cases, they also load faster as they don't get checked by cheevos on retroarch (achievments).
In Quick Menu when running a game, All the Threaded options shoud be on if not auto (Threaded Rendering and SPU). Frame Duping should be On aswell (in Tekken 3.chd the game runs smoother with Threaded Rendering on Sync so either Sync or Async try with each game).
Dynamic Recompiler it's On by default and should always be as it does help with framerate.
In gpu plugin settings turning On Hi-Res Downscaling increases fps most of the time but it does break some games, Fast Lighting is ok but doesn't really impact performance but Disabling Lighting Effects does make Tekken 3 go from 27 fps to 30 (no shadows or particles though).
Disabling Blending will make you game look worse (effects and particles) with no changes in performance so best leave it On.
The video quality is bad because my phone and recording skills aren't the best :v
(these videos are from an older version with Threaded Video On, 1.16 builds don't need it anymore).
If you want to test Tekken 3 exclusively fight Yoshimitsu in Practice mode (Forest Stage) and tinker with the settings there, that stage has the most slowdown and should be a good way to see if the changes make a difference.
(Tekken 3 and Soul Blade are the only games I found that run better without audio sync at the moment, when testing make sure audio sync is On to check if the game uncaps or not, then turn it Off to see if it runs better or only speeds up).
--------------------------------------------------------------------------------------------------------------------------------------------------------------
CORE OPTIONS (1.16 and newer nightlies)
Threaded Video: Off
Dynamic Recompiler: On
PSX CPU Clock Speed: 64
Frame Duping: On
Threaded Rendering: Async most of the time, some games prefer Sync
Frameskip: Off (user preference)
Texture Blending: On
Lighting Effects: On
Fast Lighting: On
Hi-Res Downscaling: On (Off if you want more performance, can break graphics sometimes)
XA Decoding: On
Threaded SPU: On
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Tekken 3 with V-sync and audio sync Off, Threaded Video On and Threaded Rendering set as Synchronous,
psx clock speed 55 (at higher values it does make the gameplay and some cutscenes run better but the opening cutscene, menu and the credits speed up quite a bit, I've also tested at 70 and it runs smoothly with some slowdowns depending on the stage).
N-Zero and Final Fantasy 7 tested with the same settings but with audio sync On and the cpu clock set at 80.
Gran Turismo 2 tested with the same settings as above but without audio sync (having it On only fixes the clicking, no performance increase or decrease in this one).
These settings work well for Gran Turismo 2 as tried a few races on maps I knew there was big slowdowns when crossing areas with lots of scenery (trees or houses) and now barely has any slowdown.
For some reason the cars sometimes don't display properly on preview without turning Hi-Res Downscaling On, the menu and font look worse with it but it runs better and it doesn't happen in races so yeah.
I recommend using the Duckstation cheats as you can enable Higher Draw Distance without any performance drops as far as I know so check it out (google: libretro gt2 .cht)
The Final Fantasy main games run well on overworld with a bit of slowdown when in a battle, IX slows down more that VII but it's not much of a difference, I haven't tested VIII yet but the performance should be around the same.
Azure Dreams runs great, played up to the 12th Floor.
Bushido Blade 1 runs pretty much flawlessly, the loading times are not great though.
Diablo runs flawlessly, no issues as far as I know.
Dr. Slump isn't a demanding game and runs flawlessly with this settings.
Metal Gear Solid runs at a steady 30 (at least on the first stage as I haven't played past it).
Persona 1 runs great with this settings, the first FMV was laggy the last time I tried but not anymore.
N-Gen Racing doesn't quite stay at 30 fps but it doesn't slow down much either so it's 99% playable.
Soul Blade runs great with minimal slowdown but performance drops a bit when fighting Soul Edge at stage 11.
Tony Hawk 3 runs great, finally a good skate game for 3ds.
The Tomb Raider games run well with these settings, having the same issue as FF7, but for some reason playing it at uncapped speed feels smoother (atleast on TR1). TR2 runs a tad bit slower than 1 and same with 3 but it's still playable, this is normal as they're games that use the same engine but add more with each sequent title.
The Tenchu games behave similarly to Tomb Raider, they run well capped, but it feels smoother leaving audio sync off as they're slow games in the first place, uncapping them makes the games run at fake 40FPS as they're sped up.
All the games tested are NTSC, I'm not too sure but they might benefit more than PAL ones from the clock speed increase as they have more frames to show per second, I might be completely wrong but yh NTSC better anyways.
Having audio sync On can make a difference for games that already run well enough as it fixes the clicking when audio is playing and some games need it for the FMVs/cutscenes to play properly.
The other speed hack options differ a lot inbetween games but on most games I did not find any notable differences.
------------------------------------------------------------------------------------------------------------------------------------------------------------------
Now again the psx clock:
In PCSX the psx default clock speed is 57, but if the game is in BIN format even if you can change the value it won't do anything, if the rom is CHD the value does apply, so whenever you set it past 80 (as I've tested) most games running with audio sync Off are going to have their framerate uncapped and could even black screen, flicker or break in some other way but games also uncap at default clock speed values with this change if you're playing CHD so it's better to turn audio sync On so they run at normal speed.
Turning audio sync On will cap your framerate and reduce performance slightly which is important but most games benefit from having a high cpu clock speed value and turning audio sync On (Final Fantasy 7 uncaps without it but runs well with audio sync On (Tekken 3 loses performance with it but the smoothness improves quite a lot with the setting Off).
Here's an example with Tenchu 1 with the settings above (core options):
With Audio Sync
Without Audio Sync
As you can see the game speeds up nicely but the audio clicks more which isn't really great.
Most games will run fine as long as the clock is around 64 - 80, but some speed up by around x1.25 - x1.5 if audio sync is Off so test around and see what fits your game, personally I've seen that a clock speed above 64 with audio sync On helps improve performace on most titles but games like Tekken 3 don't like getting their framerate capped and run slower if audio sync is On, (the music syncs and sounds good but it takes a hit in performance).
Turning it off makes the game jump up to "fake" 40 - 45 FPS so again, test around and see what fits.
Depending on the game disabling the Lighting Effects might not be a bad idea, It will for sure look worse but all games run better without them no exceptions (as far as I know).
(OUTDATED)
Make sure to reload the core when changing the clock speed as it might not set while running the game.
This is not all, I'll keep adding more stuff as I find but this is it for now
Last edited by NASSULY,
