That eDRAM comment has left me scratching my head as it directly contradicts lherre's statement that their is no L3 cache. As good as IBM's eDRAM is, I'm under the impression that SRAM would still be much better as L2 cache (which was put at 3 MB according to bg's sources). The only other scenario that seems plausible is the "scratchpad" theory of wsippel and others that 32 MB of eDRAM will be on the GPU but the CPU will be able to access it at a bandwidth, which is atm completely unknown, except that it needs to be at least 3.2 GB/s since it seems they're using IBM's eDRAM to mimic the 1t-SRAM in Wii BC mode. Anyone have any guesses as to what that bandwidth might be?
http://en.wikipedia.org/wiki/POWER7
http://www.engadget.com/2011/06/07/ibm-puts-watsons-brains-in-nintendo-wii-u/
The Wii U CPU will be Power7 (watson) based. It utilizes a ton of eDRAM as L3 cache and offers a lot of improvements over what we see used on the 360
It could be possible the customized GPU will have eDRAM as well like the 360's Xenos did for a super fast buffer. No clue what the bandwidth might be, but it was super