Dolphin, the GameCube and Wii emulator - Forums

I know Wii-U emulation is a dream away but I am interesting in the technicalities of such a task.

Wii U uses a Triple-Core PowerPC CPU @ 1.24Ghz
Wii uses a Single-Core PowerPC CPU @ 729Mhz

How would a multi-core powerpc be emulated, could each PowerPC core be
emulated on separate threads?

What would the requirements be to emulate the Wii U CPU ?

Without hard evidence only guesses can be made. You can just take the upgraded hardware specs and make a guess with mathematics that you will need three times the cpu cores and about two times the ghz that you need now for wii emulation. It is a highly unreliable figure but you could say it is not entirely unrealistic to expect something among those lines either. So if a four core (preferably 6 core) highly overclocked current/future intel cpu was needed to play something in a decent framerate, it wouldn't shock me...

Gir Wrote:How would a multi-core powerpc be emulated, could each PowerPC core be
emulated on separate threads?

Yes.

Gir Wrote:What would the requirements be to emulate the Wii U CPU ?

^What he said.

So is the Wii U a three core and overclock version of the Wii or is it actually a whole new architecture that has backwards compatibility?

It's ISA and microarchitecture are practically identical but not quite. They are backwards compatible. It has three PPC cores, an arm core (for backwards compatibility with starlet), a much bigger/faster cache, and 32MB of edram manufactured on a single die using a 45nm SOI process by IBM. The arm core and one of the PPC cores are reserved for the OS. And yes it's clocked a bit higher, 1.24GHz like he said.

According to delroth, the main problem isn't the CPU, it's the GPU. Flipper was pretty basic, and it was more or less just enhanced for the Wii. The Wii U GPU is an entirely different beast, built from a very modern and full featured GPU. No emulator that has existed up to this point has had to emulate a GPU on that scale before. It would SUCK.

(10-12-2013, 12:52 PM)MaJoR Wrote: [ -> ]According to delroth, the main problem isn't the CPU, it's the GPU. Flipper was pretty basic, and it was more or less just enhanced for the Wii. The Wii U GPU is an entirely different beast, built from a very modern and full featured GPU. No emulator that has existed up to this point has had to emulate a GPU on that scale before. It would SUCK.

http://wiiudaily.com/wii-u-gpu/


If it does have 400 unified shaders like this website says then its a 5550 with modern features.

It's microarchitecture is R700 based not R800. It's feature set is actually older than a 5550, more on par with an HD 4000 series card. And the number of shader units is far from the only important spec.

I've seen another website say it might be based on R800 as well. But if it is based on R700 it is between a 4670 and a 4730 when it comes to shader performance.

I'm pretty sure nintendo themselves said R700.

You cannot evaluate shader throughput based on the number of shader units alone. Its shader throughput is 352 GFLOPs putting it about on par with a 4650. Of course a number of other things effect actual shader performance so that still isn't the full story.