Multithreading

[Atom]

When is Dolphin going to start making use of 4 or more cores?

[Duke Nukem]

(12-11-2011, 01:58 AM)Atom Wrote: When is Dolphin going to start making use of 4 or more cores?

You want an honest answer: No one knows. Maybe it's possible maybe not. Either case not this year and probably not next year.

[Xtreme2damax]

Never, Dolphin can not use more than two cores. Attempting to do so would create instability and decrease speed contrary to popular belief. You would have found the answer you were looking for had you searched the forum, there are hundreds of threads explaining why it's neither possible or feasible.

[Zee530]

Due to synchronization problems, i doubt dolphin will ever support 4 cores

[Duke Nukem]

Ha ha... you guys have to excuse me but I honestly didn't know that it wasn't possible, not really something that I care about anyway.
But I guess both the OP and I know that now. Well it doesn't change anything Dolphin works great no matter how many cores it supports.

[anthonyda]

(12-11-2011, 05:04 AM)Xtreme2damax Wrote: Never, Dolphin can not use more than two cores. Attempting to do so would create instability and decrease speed contrary to popular belief. You would have found the answer you were looking for had you searched the forum, there are hundreds of threads explaining why it's neither possible or feasible.

I don't see why you are saying this, especially since there is an "openmp" option in the settings ...

[HawaiianPunch]

OpenMP provides virtually no speedup, just like LLE on thread.

[Xtreme2damax]

(12-11-2011, 06:57 AM)anthonyda Wrote:

(12-11-2011, 05:04 AM)Xtreme2damax Wrote: Never, Dolphin can not use more than two cores. Attempting to do so would create instability and decrease speed contrary to popular belief. You would have found the answer you were looking for had you searched the forum, there are hundreds of threads explaining why it's neither possible or feasible.

I don't see why you are saying this, especially since there is an "openmp" option in the settings ...

That's not what is meant by making the emulator support more than two cores. Yes we know there is LLE on thread and such, but there is no way to split the core such as CPU/GPU on any more than two cores/threads. Doing so would cause synchronization issues, instability and decrease performance. Dolphin isn't going to use more than two cores/threads except LLE on thread, texture decoders such as OpenMP/OpenCL, Wiimote/input threads and those provide virtually no speedup.

[Link_to_the_past]

(12-11-2011, 07:08 AM)HawaiianPunch Wrote: OpenMP provides virtually no speedup, just like LLE on thread.

For lle on thread you are wrong (unless if you use hle of course, since it will do nothing ).

[NaturalViolence]

Summary of situation:

Three chips to emulate: CPU, GPU, DSP
Each chip can be emulated in parallel with one another enabling three main threads. However each chip must be emulated sequentially and cannot be emulated with multiple threads. Therefore we are never going to have more than 3 main threads.

If LLE on thread is disabled or HLE audio is used than we have only two active main threads. LLE on thread can sometimes provide a large speedup depending on whether a game is being bottlenecked by the cpu thread or the video/audio frontend threads.

Many things can be done in parallel within dolphin (texture decoding, input, etc.) but none of these will provide any noticeable speedup since the main threads account for 99.99% of the workload of the application.