I’ve have similar problems with my Brick. GBA FF is set at 10 by default but still runs at 1x. GBC I noticed some slow downs but for the most part it works okay. I noticed similar things on NextUI, except GBC fast forward doesnt work there either but this is about muOS. I wonder if there is some sort of hardware problem with the Brick.
I’ve had no problems with fast forward on other devices. Works perfectly on my RG35XX SP. Works fine on my old MM+. Only device that gives me issues is the brick.
Edit: After a little testing, the gpSP’s fast forward is working fine. Occasional slow downs but playable (to me)
On NextUI I’ve never have this problem, GBA 2x, NextUI on my Brick even feel like 2.5x on my Miyoo Mini+.
Back to MuOS, it’s run just fine on my 34xxSP too, no stutter at all. Love this CFW but not sure if FF issue is fixed
If fast forward is what you are after then you don’t have to stick with MustardOS.
Unfortunately there is a lot at play here, differing RetroArch versions, core updates, audio subsystem differences. Could be a single thing, could be many. We can look into it but it’s not guaranteed that it will be resolved.
I switched to NextUI for a short time, then recently went back to check the newest Goose 2508.4. The issue seems to be resolved, just test some games on GBA and GBA. Still run into the issue if Gorvernor set to On Demand, but when switch to Performance, most of the time it’s running fine. Still got the issue on mGBA core (Pokemon Leaf Green, Final Fantasy 1) but I switch to GPSP, the issue is gone. Overall, this is a great improvement from last Goose version. Appreciate your great work