I’ve changed this to 1080p in the launch menu and now all games are running perfectly with shaders on!
Can anyone recommend an optimum resolution? Interested to see if any of the others may make further improvements.
1080p60 is the optimum really. any lower may increase performance if gpu is the bottleneck, but if it's already full speed it's not going to matter.
also, the crt scanline shaders require ~4 vertical pixels per emulated pixel for the scanlines to look decent, and 240x4=960, so 1080 is near the typical limit anyway.
finally, lower resolutions = more obvious scaling artefacts.
• Arcade/Mame/FBNeo, to change 3-4 player settings: For "in-game system menu options" (i.e. hold Start), those should automatically save a .fs file I'll be on the lookout for. ------ ones where I have to go into (Select+X) RetroArch Menu > Options to change the 3/4-player settings I'll try the "Create game-options file" which should safe a .opt file in /opt/retropie/configs/all/retroarch/config/fbneo)
like i said, you don't need to create a game-options file in lr-fbneo if these are dipswitch settings, as it will create unique entries for every game in the global /all/retroarch-core-options.cfg, so just change the setting and it will save automatically.
@dankcushions well, I have edited a few more configs and its all working fine. There is an option for resetting permissions - which I thought may have been the solution - if it happens again, that's what I'd probably try - because once it created the file itself it seemed to me ok.
ok thanks. I meant 2d games actually (maybe plus tekken and soul blade / edge but not a must). Is there any list of games supported by mame in 2003? or maybe which specific version of mame that is?
each version of MAME will have a corresponding gamelist.xml or dat file which contains the list of games it supports (however nothing about performance). there are compatibility lists linked in the retropie MAME docs but they are fairly broken right now (soon to be retired), and don't contain pi4 information.
soul blade and tekken's playstation versions will run great.
any cooling needed?
i use the flirc case which acts as a heatsink. never had any overheating issues, but it depends on your room temperature, humidity, ventilation, etc.
@sad_muso you didn't say what emulator you're using. afaik even simple shaders are often very system bus intensive, so they're constantly fighting for bandwidth with the GPU, CPU, etc. afair, lr-genesis-plus-gx really hammers the system bus, so try using lr-picodrive instead, if you're using the former.
Are they CPU/RAM intensive or both? Does the Pi 4 cope with shaders better than the 3 B?
first part answered above. pi 4 will cope better.
Do overlays cause any hit on performance, specifically when used in conjunction with shaders?
yes, for whatever reason they seem to.
What is the least expensive way to implement curve and scanlines that is currently in existence?
it depends on the shaders you are using now. for example, assuming you use 240p with your new CRT, a scanline shader would be pointless because a) 240p already shows scanlines on a CRT and b) 240p is not enough vertical resolution to allow fake scanlines to be rendered.
shaders that adjust the colour or fidelity of the image may or may not be useful or provide the desired effect, depending on what they are doing and how you are connected to your CRT.
To reply to my own post with more info...I believe this to be a bug with the Mednafen core and/or Retroarch. Possibly moreso Retroarch
Using the Vulkan renderer worked great for a while then all the sudden mid game my battle swirl went away and all i get now is a black screen with this as well. Same with the GL renderer as mentioned before if this is what you're reading. I replicated the same scenario with another device as well...
The swirls work fine initially then stopped working entirely for some unknown cause however i was reading this issue which had a very valid workaround: Github-beetle
If on both OpenGL and Vulkan you want your battle swirlies and they just stopped working start the game, toggle ANY option on and off in Retroarch then resume the game and everything is fine. I cant believe i had not even tried that even by accident...
Edit: I ended up recording a video of this along with what actually works as a fix. Keep in mind there are NO core overrides and this is with stock retroarch settings which use OpenGL.