This is an issue with all Ubisoft games using the same engine as Rayman 2. I get the same alternating 30/60 fpsfor example in Donald Duck Going Quackers too. Even Rayman3 which is DX8 is affected but I'm not sure if that's the same timing problem.

The point is, the game renderer always waits for the vertical blank period before presenting the current frame. Shouldn't do that at all, not needed since the presentation itself is done with vsync.
Reported vertical blank status may not be in sync with the real vsync (especially when running in windowed mode, unlike with the real hw back in the days) so the renderer may miss every other frame bacuse of the superfluous waiting, resulting in 30 fps.

Anyway, I remember that I cut waiting loops from the game renderer code (I've just tested it quickly again) and it runs at constant 60 fps both though Glide and DX6.

dgVoodoo Glide wrapper performance is also not so good by the way.

Shouldn't be, this isn't a demanding game at all, especially for 60 fps.

Maybe nGlide produces more accurate vsync info. I wanted to give it a try for my curiosity but I only got a blank screen for some reason.

Edit: Try the attached renderer files, Rayman 2 works perfectly for me with them.

I'm shocked.
Now it works in 60 FPS - with tex mod and even my demanding Reshade preset.

I'd like to thank you in the name of our still living Rayman modding community. That's really great thing.

I spread it out among more people.

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The game works perfectly with dgVoodoo now, so don't bother but
in case of nGlide, you can try to test 2.00 version.
I know that there were some issues with Vulkan renderer set in its configurator.

Rayman 3 is free of FPS issues, at least when it's used with d3d8to9. It's enough to download "Better Rayman" as it contains that, and few more fixes.

Best regards

I have positive feedback from users on other GPUs, and it works in 60 FPS unless run from our Rayman Control Panel app, which is not necessary. Success.

It's also worth to say that Glide is the only version where problems with seems between textures don't occur. It's not very frequent, but happens in some areas.

In DX6 it looks like this:

In Glide it looks like this:

Probably something's wrong with filtering, or maybe incorrect alpha. It occurs with and without tex mod.

But it's just FYI.

Once more, thanks a lot for the fix. It's gonna be fun playing the game again.

Those combing artifacts look oddly like z-fighting, have you tried forcing different depth buffer modes?

I pressed RBM on dgVoodoo configurator bar,
showed all sections,
got into DirectXExt,
and instead of "Depth Buffers" > "App Driven" any other setting (32 or 24 bit) fixed the problem.
Thanks a lot!