I've been studying DSP emulation for about a week now (to implement in Gekko), so here goes.
Yes, LLE's audio quality is linked to the emulated game speed. Unlike HLE audio in Dolphin, which can simply mix the audio longer, LLE doesn't time stretch. That said, if the GPU bottlenecks emulation, then of course game speed and overall performance will be linked to things like IR. If your GPU slows you down, it'll necessarily slow down LLE. That does not mean LLE is the cause of the slowdown, it just suffers from the affects.
Note that LLE audio, by nature, is more demanding than HLE, so if your computer can't handle it, you're going to take a performance hit, and consequently get poorer audio results. Resolution makes no difference to LLE's performance. The DSP is emulated on your CPU, but Dolphin uses your GPU to emulate GC/Wii graphics. Things such as anti-aliasing, anisotropic filtering, and internal resolution are all handled by your GPU. If LLE works fine on lower resolutions, but an increase in resolution results in issues, the problem lies with what you changed: the resolution.
Like I said, it's not LLE's problem, it's your GPU. At higher resolutions, your GPU becomes the bottleneck, slowing down the rest of your computer. This slowdown affects LLE. LLE requires more resources because it more accurately emulates the DSP, much closer than HLE. That accuracy comes at a price though in terms of computing resources. When you reach full-speed with LLE, the results are often better than HLE, simply due to how closely it matches what a real Gamecube/Wii DSP would produce.
Frame skipping shouldn't let games run at full-speed. All frame skipping does is tell the emulator not to draw a certain number of frames. Dolphin still knows what the frame should look like, it just doesn't display it. It won't change the emulated game speed. If you're not getting full-speed, frame skipping shouldn't change that.
Since LLE is so demanding, you really shouldn't try running it unless you can get full-speed with HLE. Also, frame rates are not the most accurate measure of game speed. When Dolphin is run as a windowed application, it should display the emulated game speed in a percentage. That'll tell you if you're getting full-speed or not. Also, #2 doesn't make sense. Why would LLE audio be unusable if my GPU is performing at 99% of what I want? The more likely culprit would be poor game speed due to bottlenecks in the GPU, CPU, or both.
Just trying to hit it home, but DSP emulation is dependent on your CPU. The GPU has no say in that performance unless it becomes the bottleneck for the rest of the system. I've run Tales of Symphonia just fine at 4x with LLE (though I don't have a monitor good enough to anything greater than 2x atm...) At least according to Wikipedia, my own GTX 550 Ti is only upper-middle class when it comes to other GPUs, but for Dolphin it does just fine for high internal resolutions with LLE audio enabled.
(03-23-2012, 06:02 AM)etking Wrote: In LLE, audio speed is linked to game speed. This is the major problem. Game speed is (in)directly linked to internal resolution if you do hot have an high-end GPU. If you not always reach full frame rate (as the case for most average users), LLE is completely useless.
Yes, LLE's audio quality is linked to the emulated game speed. Unlike HLE audio in Dolphin, which can simply mix the audio longer, LLE doesn't time stretch. That said, if the GPU bottlenecks emulation, then of course game speed and overall performance will be linked to things like IR. If your GPU slows you down, it'll necessarily slow down LLE. That does not mean LLE is the cause of the slowdown, it just suffers from the affects.
(03-23-2012, 06:02 AM)etking Wrote: Reality (and logic) shows that LLE runs much better in lower internal resolutions on my System (Dell XPS 17 notebook with overclocked GT555M). I use EFB to Texture, LLE on thread makes no real difference. LLE audio works much, much better in lower resolutions but HLE audio is always 100.000 times faster anyway. So no need for LLE at all. As long as there is no automatic frame skipping in dolphin HLE is completely useless for me. The average user has no high end graphics card, so I cannot understand why using the (performance-wise) inferior LLE is always recommended? My GPU is just to slow for running LLE sound at full speed, this is really trivial. (I know that Sound runs on CPU only but audio speed in LLE is linked to game speed and game speed is limited by GPU in both HLE and LLE)
Note that LLE audio, by nature, is more demanding than HLE, so if your computer can't handle it, you're going to take a performance hit, and consequently get poorer audio results. Resolution makes no difference to LLE's performance. The DSP is emulated on your CPU, but Dolphin uses your GPU to emulate GC/Wii graphics. Things such as anti-aliasing, anisotropic filtering, and internal resolution are all handled by your GPU. If LLE works fine on lower resolutions, but an increase in resolution results in issues, the problem lies with what you changed: the resolution.
(03-23-2012, 06:02 AM)etking Wrote: Many user are using HLE hacks because LLE is not applicable and unusable for them as well as for me.
The reason for my LLE problem is that my GPU is to slow. It sometimes cannot reach the maximum framerate. The limited framerate causes the audio to slow down or stutter in LLE. If I reduce the internal resolution and always reach full framerate, LLE audio runs fine! Why?
And as LLE requires much more resources and is inferior in almost any way, why even consider using it? I'd need a much, much better system for LLE in 1080p, a Core I7 and a GT555M is not enough.
Like I said, it's not LLE's problem, it's your GPU. At higher resolutions, your GPU becomes the bottleneck, slowing down the rest of your computer. This slowdown affects LLE. LLE requires more resources because it more accurately emulates the DSP, much closer than HLE. That accuracy comes at a price though in terms of computing resources. When you reach full-speed with LLE, the results are often better than HLE, simply due to how closely it matches what a real Gamecube/Wii DSP would produce.
(03-23-2012, 06:02 AM)etking Wrote: HLE causes massive audio bugs whenever the framerate is slower than expected. And I am sure the low framerate is caused by GPU. Why is there no automatic frame skipping in dolphin to ensure audio can always run at full speed like in many other emulators? To skip a fixed number or frames is not really helpful here.
Frame skipping shouldn't let games run at full-speed. All frame skipping does is tell the emulator not to draw a certain number of frames. Dolphin still knows what the frame should look like, it just doesn't display it. It won't change the emulated game speed. If you're not getting full-speed, frame skipping shouldn't change that.
(03-23-2012, 06:02 AM)etking Wrote: 1. SMG2 runs quite nice on my PC with HLE. It may not be always be fullspeed but I do not notice any slowdowns when not looking at the framerate counter. In LLE I have massive audio issues in 1080p as mentioned before. This is because in LLE audio speed is linked to game speed and minor changes can make huge difference for human perception. LLE is unusable for me and therefore not even an option as i do not want to reduce my internal resolution.
2. I never told something different. But for higher resolutions you need a better GPU, this is trivial. If your GPU only is capable of performing at 99% speed at the desired resolution, you just cannot use LLE audio. Especially if the framerate is not stable.
3. Only if you have a high end GPU which most users dont. For these (most) people GPU is far more important (or both are equally important)
Since LLE is so demanding, you really shouldn't try running it unless you can get full-speed with HLE. Also, frame rates are not the most accurate measure of game speed. When Dolphin is run as a windowed application, it should display the emulated game speed in a percentage. That'll tell you if you're getting full-speed or not. Also, #2 doesn't make sense. Why would LLE audio be unusable if my GPU is performing at 99% of what I want? The more likely culprit would be poor game speed due to bottlenecks in the GPU, CPU, or both.
(03-23-2012, 06:02 AM)etking Wrote: Yes it does, unless you have a high end GPU. But most people do not have a high-end GPU. Even I dont, my GT555M is just lower middle class and causes massive LLE audio slowdowns.
Just trying to hit it home, but DSP emulation is dependent on your CPU. The GPU has no say in that performance unless it becomes the bottleneck for the rest of the system. I've run Tales of Symphonia just fine at 4x with LLE (though I don't have a monitor good enough to anything greater than 2x atm...) At least according to Wikipedia, my own GTX 550 Ti is only upper-middle class when it comes to other GPUs, but for Dolphin it does just fine for high internal resolutions with LLE audio enabled.
