Why is OpenGL around 30% slower now compared to 4.0-399?

[drhycodan]

Every game I've tried with the latest Dolphin now runs 20-30% slower than it did before in 4.0-399. I've only tested OpenGL so far, but I am using the latest nvidia 332.21 driver so it should be as fast as it used to be with the VSH enabled but it's not. Does anyone else experience a major slowdown in OpenGL compared to 4.0-399?

[degasus]

You can try to use this one as it's the last before the removal of the vsh: https://dolphin-emu.org/download/dev/b49c09c36b67efc95abe29894620b36547b69d3b/

[drhycodan]

Yeah I know, but my concern is how come I can't get the speed I used to get in OpenGL with VSH enabled when I'm on a GTX 780 with 332.21 driver?

[JMC47]

I had no speed losses on the removal of the Vertex Streaming Hack on a GTX 760. I tested quite a few games, it's possible that I missed some user cases though.

[drhycodan]

It's possible the games you tested were really light games and didn't need the VSH to run full speed in the first place. Try running the opening of Metroid Prime to the point where you first see Samus' ship with OpenGL. It now slows down to 60% during that cutscene where I was getting 100% before with the VSH enabled.

[KHg8m3r]

I gotta say, I also ran into this issue. I lose a pretty decent amount of fps over most of my games after the VSH went away.

[Shonumi]

@drhycodan - It would probably benefit the developers to know which games you've played and noting the exact differences in FPS. If relying on the OpenGL spec (instead of hacking around it) does indeed drop the FPS significantly on games they or most other people haven't tested, I should think they ought to know the games affected. Screenshots would be nice, but simply listing the games (with each revision tested of course) would be very helpful. As always, you can make an issue for this on Google Code (if there isn't already one?).

[drhycodan]

well, ZTP seems to experience an overall fps drop everywhere, not just hyrule field. I can't even run that game anymore at full speed with EFB to RAM and LLE audio on a 4770K @ 4.3ghz. Metroid Prime also as stated above. I didn't really test anymore than that since I can no longer get full speed in ZTP with literally the fastest CPU you can get for Dolphin and a GTX 780. I went back to the older rev. and tested with VSH off and it literally is running just like that.

[KHg8m3r]

I'll check for an open issue /make a new one in the morning when I can test more of my library.

[degasus]

ztp is because of a different commit: https://code.google.com/p/dolphin-emu/source/detail?r=b49c09c36b67
https://code.google.com/p/dolphin-emu/issues/detail?id=2499#c27

drhycodan: I've posted the build before vsh removal, so if you'd tried this one, you'd noticed it yourself