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?
Wii U hardware discussion and investigation *rename
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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?
One what? One memory channel? One channel is 64-bit. Power7 has a 512-bit interface, hence 100GB/s with DDR3-1600.
The DRAMs in a DIMM are usually either x4 or x8 width each -> 16 chips x4 or 8 chips x8 = 64-bit I/O per DIMM. There is also memory bank switching so you can expand capacity without using more I/O.
Blazkowicz
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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.
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.
An interesting post from sebbbi a few months back: http://forum.beyond3d.com/showpost.php?p=1646788&postcount=15
Would have to wonder if the 32MB eDRAM changes much considering how much of it will be used for just render targets and various buffers (post-processing/offscreen/shadows etc).
At the same time, I'd wonder about the ability to handle larger assets (i.e. texture filtering, triangle raster rate) anyway. hm...
Would have to wonder if the 32MB eDRAM changes much considering how much of it will be used for just render targets and various buffers (post-processing/offscreen/shadows etc).
At the same time, I'd wonder about the ability to handle larger assets (i.e. texture filtering, triangle raster rate) anyway. hm...
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.
You mean this?
Something's quite off in the first part with the ground texture on WiiU (missing normal map or just lower res texture? The video is compressed to hell). edit: is there a day/night cycle?
The last part of the video looks like they increased the cascade shadow map res a bit (cascade switches a bit further out). The video is again too blurry to tell much about texture filtering (other than they're both equally shit).
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Anyways, yes higher filtering modes does mean increased bandwidth consumption via increased texture sampling requests to main memory. On WiiU? Who knows how the texture cache is setup, but even so, anything within the last few years is significantly larger than the 32kB that Xenos texture units have. A larger texture cache would reduce the amount of traffic to the larger memory pool.
The other thing to consider is also filtering rates.
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.
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:
Give mucho thanks and condolences to Anand for sacrificing his unit the photos and die size measurements. Wii hardly knew U.
CPU: 32.76mm^2
GPU: 156.21mm^2
3rd die: 2.65mm^2
... 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?
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