Retroarch 1.7.5 causing FPS drops for CPS 3 games

Darksavior

@RedBatman If fps drops below 60 in any game then expect scratchy audio. The situation is the performance of fba, with at least the cps3 driver, got a huge slowdown with the latest version.

RedBatman

Hmm so is there any way to roll back the update or is there going to be a fix eventually? CPS3 are some of my favorite arcade games.

Darksavior

@RedBatman No idea if it'll be fixed. Post the issue on fba's github. You can extract .42 from the official premade image.

grant2258

When an emulator improves sometimes it comes with a cost of speed. Other times its speed up hacks accidentally removed. Retropie runs on more than a pi.

If this problems exists on more powerful machines it would be a problem at that point.

RedBatman

Hi I just wanted to say I found a fix. I downloaded Ir-fba-alpha2012. Once I used this my CPS3 games were back to 60fps with no audio stutters or anything. So just to let this be known that if FBA 2.97.43 ever gets fixed again or its still causing issues then FBA 2012 is now needed for CPS3 games now for raspberry pi users.

Darksavior

@grant2258 Yes, that's what I experienced with the 4player Konami games. I need to use fba2012 for my pi2 (when I was using it). Still, I'd like a definitive answer if the cps3 problem is a mistake, or just emulation accuracy making it slower.

grant2258

I only use that core havent looked at the code base to be honest just check the history in the cps3 driver in github to see the recent changes here.

https://github.com/libretro/fbalpha/commits/master/src/burn/drv/cps3/cps3run.cpp

grant2258

you could try revert d313472bf07332ee429a80f906252dca348975e5 commit compile and see how it runs

https://github.com/libretro/fbalpha/commit/d313472bf07332ee429a80f906252dca348975e5#diff-d51bfb6a692321f4224209e955b76d48

Darksavior

@grant2258 No idea how to do that.

RedBatman

@grant2258 said in Retroarch 1.7.5 causing FPS drops for CPS 3 games:

you could try revert d313472bf07332ee429a80f906252dca348975e5 commit compile and see how it runs

https://github.com/libretro/fbalpha/commit/d313472bf07332ee429a80f906252dca348975e5#diff-d51bfb6a692321f4224209e955b76d48

I don't know how to do that either. But if FBA 2012 works good still then I'm fine with it, just as long as the current fba doesn't get any worse.

DarishZone

There's a way to revert to an older version of Retroarch?

UDb23

@RedBatman A new version is available. Is the issue still there ?

Darksavior

I retested using lr-fbalpha 2.97.44 from source. No change. To compare the differences to .42, using my pi3b+ overclocked to 1450, it runs as fast as a stock pi3 non + used to run at which is 60fps most of the time with dips of ~59.5-.7.

barbudreadmon

Ok, i didn't know about the speed regression. There was indeed a huge CPS3 patch a few weeks ago to fix some bugs (it was mostly for jojoba actually, until very recently the combo meter in this game wasn't working properly in any emulator, see https://mamedev.emulab.it/haze/2018/10/02/little-changes-part-2/ for the news). I'll look if something can be done about it, however i won't revert a fixed code to a buggy code, as far as i understand this bug is not even happening if you own a rpi3b+ or if you overclock your rpi3...

Darksavior

Pi3b nonplus at 1300 with SF3:
.44 from source using default compile: Supers drop to ~58.x fps.
.44 from source using altered compile settings: Supers drop to ~59.xfps.

I believe this is the part that helps but I'll post the patches link for system.sh. I basically added all the green text and removed the red text. I replaced -O2 with -O3. YMMV. Supposedly -O3 " there's known issues in GCC 6.3.0 with some of the optimizations it enables."
+ __default_cflags="-O3 -march=armv8-a+crc -mtune=cortex-a53 -mfpu=neon-fp-armv8 -mfloat-abi=hard -ftree-vectorize -funsafe-math-optimizations -funroll-loops -funswitch-loops"

https://gist.github.com/GrieverV/b3d1a8e2c23c295b802f9e33286437c6

barbudreadmon

@Darksavior except if retropie build script is totally ignoring my fbalpha makefile, i think the relevant part in what you wrote is -funroll-loops -funswitch-loops :

-ftree-vectorize is included in -O3, which is the fbalpha default
afaik -funsafe-math-optimizations should only have an impact on games using a lot of arythmetic function, it shouldn't be the case for cps3 (on a sidenote, raiden2 uses them a lot)

Thanks for the information, i'll do some tests and if those flags are interesting speed-wise, i'll add them to default fbalpha cflags.

Edit : actually -funswitch-loops is also part of -O3, meaning only -funroll-loops is relevant.
Edit2 : i've been thinking for some time that this change is the culprit, so having a speedup with -funroll-loops makes a lot of sense actually.

barbudreadmon

Do you guys have rewind disabled for cps3 ? While it was kinda ok to let it enabled previously, recent updates won't allow it anymore speedwise.

Darksavior

@barbudreadmon It's disabled by default so it's not enabled for me.

barbudreadmon

@Darksavior -funroll-loops is now part of the fbalpha makefile.

barbudreadmon

@Darksavior Another commit was applied to the fbalpha cps3 codebase today, it appears part of the jojoba combo meter fix could be optimized. Let me know if the slowdowns still happen.