There's plenty we don't know about the Wii U's components but let's have a look at what we do know:
The 360 has 1MB of CPU cache, the Wii U has 3MB of cache and eDRAM has improved over the last 8 years (although WiiU uses eDram that has more or less the same performance as the original Wii SRAM, but it would be good to have a comparison of cicles wasted between the WiiU and the Xbox360).
The 360's CPU is In-Order and has to deal with sound, IO and OS functions. Expresso is Out-Of-Order, meaning there are less idle cycles, and doesn't have to deal with those tasks thanks to the Wii U having a DSPand ARM co-processor. To have a much more complete picture. The Xbox360 has a huge pipeline of more than 30 stages that has of course huge penalizations when it comes to pipeline stalls. It also runs at 3,2Ghz compared to the Espresso's 1,243Ghz and to mitigate the lack of OoE can run two threads of code in every core. Since the 1MB of L2 cache is shared, the more threads you run the less caché avaliable for each core.
Caché can be programmed in both processors (Espresso and Xenon) to improve it's use.
The GPU in the 360 has a DX9-equivalent feature set, Latte has a DX11-equivalent feature set. Latte is also faster (550Mhz vs 500Mhz of the Xenos) and has some sort of hardware functions a la TEV which are adapted to the standards required for the WiiU.
The 360 has a tesselation unit, but it's pants. The Wii U has a more modern tesselation unit which according to Shin'En is usable.
The 360's GPU has 10MB of eDRAM on a daughter-die, Latte has 32MB of eDRAM and 3MB of SRAM on-die. The 32MB of on-die eDram and the (2+1MB) are the main memory of the WiiU. Unlike the Xbox 360 eDram which can only be written by the GPU at a maximum bandwidth speed of 32GB/s, the eDram on the WiiU can be written and read by both the GPU and the CPU so the buffers and data written on it doesn't have to travel to the big pool of RAM to be passed again to the CPU/GPU for it to be read.
The 360 has 512MB of RAM, the Wii U has 2GB of RAM with considerably less latency. The maximum bandwidth of the Xbox 360's big memory pool is of 22.4GB/s, while the bandwidth of WiiU's big pool of RAM is of 12.8GB/s (faster RAM but with a 64 bit bus).
The fact that the WiiU uses a MCM design and that the northbridge is located on the GPU in both consoles, reduces the latency between the main memory and the CPU even more than the fact that the WiiU's memory has lower latency itself).
Of course, the communication between CPU and GPU is also much faster due to that.
The 360 as a whole has bottlenecks coming out of its ears, the Wii U has been designed specifically to avoid bottlenecks.Yes, but this is not data per-se. I mean, this is something that can be seen when looking at the whole points that we pointed before, not anything that adds information that wasn't listed before.
And we don't have a Scooby Doo what half of the silicon in the GPU does, but we do know that the Broadway in the Wii outperforms Xenon in the 360 at general processing tasks and that Expresso, whilst being a different chip, must share some similarities...and no, it's not 3 Broadways duct-taped together lol.Well, Nintendo and other developers have given clues to us. For example, we know that it has a tessellation unit (we were told by Shin'en), a new texture compression algorithm also compatible with the one used on the Wii (a superset of it maybe or an entirely new one + the one used on the Wii) and some other Wii functions adapted to work with WiiU games confirmed by Iwata himself.