(GL)Weird Inconsistent FPS

[Spirrwell]

I... am just so very confused and I apologize if this has been posted before because there's already numerous questions about FPS related issues, but I just... don't get this.

In the past I've always been focused on getting the Legend of Zelda Twilight Princess (GC) to run lag free. I've heard a lot of the same things over and over about it being a very demanding game and how it will run better under HLE, and etc.

While it does run a bit better under HLE, it's still imperfect. Even using the patch Hyrule Field is laggy... But, if I start the game with the frame limit off, go into game and switch over to Auto or Audio, it doesn't lag... If I do it the other way around, then the opposite is true. When I turn the frame limit off it will still be below 30 FPS.

And just playing the game with the frame limit off it runs very fast despite that the speed you know, distorts the sound. It seems to always be above 30 FPS if I turn the frame limit off. Also, to be a bit more specific, if I run the game with the frame limit off, go to Hyrule Field, then set it back to Auto or Audio, it works as it should. However, if I switch back before transitioning into Hyrule Field, this does nothing, the FPS is below 30.

This weird FPS increase that comes out of nowhere if I start with the frame limit off eliminates the need for the Hyrule Field patch. It runs at a solid 30 FPS without it by doing this. So um... what in the world is going on? My brain is hurting, I don't get it, this does not make any sense to me.

Any information would be appreciated, also, I'm sure my signature is wrong about my Dolphin version, I'm using Dolphin 4.0-2241 right now.

Edit: I noted in the title that I was using OpenGL, however the same weirdness is also achievable with Direct3D. But it's just all around inconsistent...

[KHg8m3r]

Really there's not much to do besides overclock more.
However, you would need one of the Haswell refresh i5-4690K/i7-4790K/Pentium G3258 (overclock-able)

As you progress farther into the game, Hyrule Field makes the game slow down as you progress more and more. They're looking into ways to make it speed up more, but you're just going to have to live with the slower speed until it's fixed

[Spirrwell]

Er... my point was not that it was slow, but that I could make it go fast if I start with the frame limit off. Why does this happen? My question isn't why is it slow, it's why is it fast under these specific circumstances? Shouldn't the speed always be limited purely by what the hardware is capable of? Or is there something else going on?

[JMC47]

There are tons of conditions that can cause irregular slowdown. Shadercache generation will cause short stutters the first time an effect is loaded, underclocking GPU/CPUs can cause a huge variance in performance, other issues... tons of things can happen, more or less.

[Spirrwell]

While I understand that multiple factors can influence slowdowns, why does this in particular cause the game to speed up? I'm not talking about the slowing down, I'm referring to the speed up under these specific circumstances.

[JMC47]

I've had issues where GPU underclocking has caused huge fluctuations in framerate.

[Spirrwell]

Oh! Duh, throttling! Right. I'll check that!

Edit:

...Heh, I think you were right, I just didn't understand what you meant by "underclocking" at first. Thought you meant not having it overclocked enough. XD Of course after I went to reboot my computer and check this, the problem stopped. However, I did notice that when occasional stutter happened, the GPU had throttled down to about 824 MHz, and it would even throttle down to 324 MHz when transitioning to another area. I'm sure I'll be able to find a way to stop it from throttling through software, but I think that was the issue. My guess is that the GPU was throttling down to 324 MHz and staying there before I rebooted.

I also know that when the display drivers crash and restart, that usually forces it to a lower speed. Which has happened. Thank you so much though!