Wii U hardware discussion and investigation *rename

Would this have anything to do with the DDR3 memory controllers that IBM uses with Power7? Because we dont know yet what technology the CPU shares with Watson.

Power7

Maybe WiiU is using one of them?

 

Actual speed can be debated, IMO Nintendo make quite a sacrifice by only using 64bit ddr3, so it wouldn't be wise to use their chips at their lowest rated speeed. Using them at 2133 makes sense, to hell with the tiny difference in power and reliability. Just use high CAS latency setting (but, with the higher frequency, the latency doesn't really move), suck it up.
But the ddr3 memory controller would have to work good.

 

Do we really know if it's bandwidth starved ? I mean, except for devs working on it, we don' t really know how the data are moved around the system, what are the real penalties for slow main memory, etc... ?

 

I think it's a safe assumption, unless there's actually like 256-512MBs of embedded memory instead of just 32MBs. 32MBs isn't enough to magically compensate for the DDR3's limitations.

 

There is an exact number on this site about the used rams (note that it's not Samsung this time):

.According to the pdf, these are the numbers:

Data rate(MT/s): 1600
Target tRCD-tRP-CL: 11-11-11
tRCD (ns): 13.75
tRP (ns): 13.75
CL (ns): 13.75​

 

That's not really my area of expertise, but I just watched a comparison between Darksiders 2 on 360 and Wii U, and the Wii U version apparently has an extended texture draw distance. Wouldn't that require more bandwidth?

 

I perfectly aware of that, just linked an info about the Micron rams what we can confirm from the pictures, and what was not referenced here before, that's all.

 

Textures switching from lower resolutions to higher resolutions at a greater distance.

 

Maybe caused by the use of anisotropic filtering (or no positive LOD anymore?).

 

So I've been thinking about chip sizes and that. We don't know that TSMC are making the GPU, but just for the sake of throwing some numbers around, according to this (with "Taiwan Semicond. Manuf. Co. Ltd." listed as one of the authors):

http://ieeexplore.ieee.org/xpl/logi...re.ieee.org/xpls/abs_all.jsp?arnumber=5872231

... you're looking at 0.145 mm^2 per Mbit of edram on their 40nm process. So that's 37.12 mm^2 for the rumoured 32MB.

With a die size of 156.21 mm^2 for the GPU:

... that leave you with about 119 mm^2 for everything else.

 

Well that pretty much excludes the RV740 due to the fact that the chip was 137mm^2, doesn't it?

 

Reduce the memory bus width, ROPS and other various parts and it'll fit.

 

With a few SIMDs removed (and the DP support nixed), it could be an option. But why not using a Redwood (104mm²) or Turks (118mm²) as base right from the start (better suited for GPGPU)? Remove half of the mem controller (-10mm²) and you probably have some space for a bit SB functionality/connectivity. That is integrated there too, isn't it? Or is it in the CPU chip?

Edit:
I wouldn't want to remove ROPs. With a fast eDRAM on die, one would loose too much for the small die size saving in my opinion.

 

Thought I was actually being useful for once!

I posted on that damn page too! Post without reading to the end of the thread, then forget to read the rest of the thread, then just continue reading from your last post next time, because, like, that must have been where you read up to last.

Well RV740 has a double width data bus, and it's GDDR5 which requires more pins iirc, so maybe you could squeeze it into less than that in the WiiU. But on the other hand the edram would need some kind of controller and CPU bus (presumably wider than PCI-E), and then there's Nintendo's Audio DSP and Arm processor (or is that the 3rd tiny die?) and probably some other stuff too so ... I dunno.

Would seem odd for Nintendo to skimp on the CPU, memory bandwidth, power and cooling, and actually pack in a fairly fast GPU. And with the main memory bandwidth being so low would 32 texture units (double the 360s) really be worth it?