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ethomaz on 29 January 2013
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Aielyn said:

"in 40nm there is no way you can put a GPU over 500 GFLOPS in this space"

This confuses me, as the E6760 itself was produced on a 40nm process. So clearly this claim is false, unless you're talking about the size of the chip itself (in which case, why say 40nm?). And the GPU die size is 156.21 mm^2 (source), compared with the E6760's die size, which is just 118 mm^2 (source). Indeed, at the 40nm process, and a die size not much higher than that of the Wii U's GPU, with a clock speed that isn't multiples larger (675 MHz rather than 550 MHz), the Radeon HD 6850M manages to push 1080 GFLOPS. Factoring in the clock speed difference, this would be equivalent to 880 GFLOPS at the Wii U's clock speed... so what was that again of not being able to get a GPU over 500 GFLOPS in this space?

Some have been suggesting that it might be based on the ATI Radeon HD 4770, which is a 40 nm process, with a slightly smaller die size, clocked at 750 MHz. It pushes 960 GFLOPS. Underclocked to 550 MHz, this would lower the speed to 704 GFLOPS, and due to the non-linear nature of power requirements for processors, this would also significantly reduce the power draw. Also note that the 4770 is a 2009 chip, so it's not like it needs to be new tech for this to happen, either.

Meanwhile, the thread you linked to starts in July 2011, and lasts for 175 pages. I'm not going to read through 175 pages to try to find the "common sense" you claim is somewhere hidden within it. You're going to have to do better than to make a vague argument with at least one verifiable inconsistency, and then point to a 175 page thread's first page, which contains posts from a year and a half ago.

Now, unless you have a source backing up your claim that it's a 400 GFLOPS GPU, or can provide a more solid argument the one I just tore apart, don't bother responding again.

The Wii U GPU die size is 156mm^2 with eDRAM... 32MB eDRAM... without it the part of die for the GPU alone is below 104mm^2.

For over 500 GLOPS using the HD 7000 arch you need at least 480 SPs running at 550Mhz (I'm using the Wii U GPU clock)... 480 SPs in this arch have a die size of ~115mm^2... that is bigger than 104mm^2 of the Wii U GPU.

The HD 4770 (704GFLOS @ 55Mhz) have a die size of 137mm^2... bigger than the 104mm^2 too.

There is no AMD tech to put over 520 GFLOPS in 104mm^2 running at 550Mhz... or you have a die size bigger or you run the GPU at higher clock to archive over 500 GFLOPS.

You know witch AMD GPU fits exactaly in the 104mm^2? Radeon HD 5670 (Redwood)... 400 SPs @ 550Mhz = 440 GFLOPS.

Remeber... the 32MB eDRAM uses at least 55mm^2 of the 156mm^2.