Wii U GPU new info and more speculation

[unaveragejoe]

Aielyn said:

RazorDragon said:
I guess my understanding of the HSA technology was wrong, then. I thought it was only applicable to APU solutions and not on separate CPU+GPU solutions. Based on what i understood, you're talking about the GPU containing some CPU logic and thus being somewhat an APU, so Wii U's MCM would actually contain a CPU and an APU, is that right? That's actually a quite interesting theory and, in theory, it would be possible, altough i don't see why Nintendo would choose to use a separate CPU and an APU instead of just using one big die with both the GPU and a complete CPU, not just some logic, in a more common APU setting. It would also explain Iwata talking about how important the GPGPU functionality of the console is, even if the GPU had only 160SPs, for example, the embedded CPU logic would give the GPGPU funcionality quite a boost. However, I don't think AMD would allow to put IBM's CPU design on their APU chip, and if AMD did that CPU logic inside the GPU, then there would be a lot of problems utilizing it thanks to the difference in x86 and PowerPC achitecture. I mean, i'm no expert either, so what i'm talking here might be worth nothing, but what you said could be possible, after all, there's still 30% unknown in that GPU and this unknown part is close to where you pointed.

Keep in mind that I'm not saying that it does have it, or anything like it. I was primarily explaining what unaveragejoe was talking about, and then was inspired to compare CPUs with Latte, just to see if it could actually make sense.

As for why they'd have an AMD APU and an Intel CPU on the same MCM... the obvious explanation would be that the Intel chip can run the OS and handle backwards compatibility (GC and Wii both had Intel CPUs - note that Espresso is understood to have a very similar processor to the Wii in terms of core architecture), while the APU could handle games, with the CPU helping out where appropriate.

There's an interesting thing to notice about the Wii U's MCM and the location of the RAM around it - it's all much closer to the GPU than the CPU.

The large square on the MCM is the GPU, the smaller one is the CPU. The RAM is on the right side. Why position them like this? I'm not saying it's meaningful, because it very well might not be - but it could be evidence.

Essentially, the question is whether we're really understanding the architecture of the system. There are so many possibilities we haven't accounted for, yet, and this is just one of them. Note that there's also the question of the third chip on the MCM - what is that smaller chip (just below the GPU in the above image)? There's been some speculation, but nobody actually knows at this point.

Note that I looked at the CPU for inspiration when making the comparison - I also looked at Llano, which is an AMD chip, because it should more resemble that than the CPU.

Everyone compares to Llano, by the way... which is a 28nm APU. What if we compare with a 40nm APU like Zacate?

Look at the section marked "CPU Core". Now, compare with what we see on Latte, in section D. To me, there's definitely a similarity, although I can't be sure. I also see something similar in X. An interesting thing to note is that some, including that Marcan guy, have speculated that Y is the equivalent of the Wii's own CPU-core-on-the-GPU, Starlet, which people have taken to calling Starbuck as a dual reference to coffee and Starlet. Indeed, Y looks a fair bit like the "centre" part of the two CPU cores (the top half of the bottom core, and the bottom half of the top core) of Zacate, while the bottom part of X looks a lot like the other halves of the Zacate cores.

Anyway, it's food for thought.

 

I think you meant IBM instead of Intel.