Umm... not quite.
http://en.wikipedia.org/wiki/Wii_U#Technical_specifications
"based on" doesn't mean it's a full featured one, and that's only a rumor.
The 4730 is "based on RV770", and that's not exactly radeon 4870 class graphics.
http://www.engadget.com/2011/06/14/wii-u-has-last-gen-radeon-inside-still-more-powerful-than-ps3-a/
"At its heart is a chip similar to the R770 found in AMD's last-gen cards like the 4890"
Not sure what the 4730 is. Never heard of that GPU. RV770 on the desktop was a 4850 or 4870, both with 800 SPs, 40 TMUs and 16 ROPs. The other version was the 4830 with 640 SPs, 32 TMUs and 16 ROPs. Any of the 4830/4850/4870 chips are at
least 2x faster than Llano's GPU.
So much baseless speculation here...
All the presently sold consoles use an "APU", or a single chip with both the CPU and GPU. ..............This is enough to get to the performance of 5770 or so, which is probably good enough.
I was under impression that Xbox360 included a GPU + CPU on 1 package but 2 separate silicon die. I heard that MS was supposed to launch a new revision that would finally combine the GPU+CPU on 1 die. But even if you are correct, it took 5 revisions preceeding
Vejle revision before the GPU+CPU were combined into an APU style setup. So it actually makes more sense that they have 2 separate die to start and then once technology reaches 11nm, then they may try to combine them once more.
Consider that HD5770 on 40nm occupies 170mm^2, how do you propose they'll combine such a large GPU on top of a Bulldozer (4-6-8 core), which itself hasn't even launched due to delays? But not only that, by the time PS4 and Xbox3 launch in 2012-2013, an HD5770/HD6770 GPU will probably be $50 on the market (considering they are $100 today). It would be
laughable to include such a slow GPU in a PS4 / Xbox3, which are probably going to launch at $400-500. It's going to be
even harder to integrate a GPU faster than the HD5770 inside a CPU die on a 28-32nm process. Consider that Llano's GPU is just half the complexity....so obviously it's extremely expensive and difficult to do.
I think you guys are too optimistic about the APU setup - you have memory bandwidth limitations and TDP constraints and a large die size actually increases costs and reduces yields over 2 smaller die until the manufacturing process has matured where it is actually cheaper to produce a single die. However, combining a modern quad-core 32nm CPU like Bulldozer or IBM's Processors with a modern 32nm GPU design is going to result in a huge die - think 400-500mm^2.
If they choose APU design at this time, the GPU performance will take a huge performance hit. The fact that Wii U didn't even go with an APU style design sends a signal that it's even less likely that PS4 and Xbox3, which are likely to include
a more powerful GPU, will follow that route either.