I thought I read LPDDR4 RAM can run up to 32GBps ... wouldn't that match/exceed the PS3? 

Does any mobile chip use eDRAM by the way? Or something similar?

Chips are evolving very quickly indeed!

pretty interesting!
the main reason i didnt believe in the fusion console was that i thought a 200$ handheld couldnt run games the home console would run.(in a level above wii u)

in more 1 or 2 years, with some natural improvments of the chip technology, i think we can see the next nintendo handheld running ps4 game visuals at 640p(max) and recuced bandwidth for 200$, and a home terminal for 300$ a step above ps4, but with the same handheld architecture. man, not bad.
most of library shared and bam, can work!

They do.

First, AMD also produces ARM Chips, although they use them for small servers.

Second, there are the E2-micro, A4-micro and A10-micro. Especially the latter, A10-micro 6700T, an x86-64 APU, is a quadcore which clocks at 1.2 Ghz base and 2.2 Ghz Turbo and GCN graphics (2CU, for comparision the Xbox ONE has 12 and the PS4 has 18) while only having a TDP of 4.5W and was actually designed for Tablets. Might be slightly slower but not by very much.

How would this stack up against the X1 chip that nvidia used in Shield?

Both AMD and NVidia where, and probably Intel, too. They use it differently, though.

NVidia wants to use HBM (High Bandwith Memory) on their Tegra Chips as on-chip memory, eleminating the need for additional memory chips. No infos about using it on future Graphics Cards yet, though.

AMD wants to use HBM in 2 different ways. First as a high bandwith Last-Level-Cache on their APUs with the size of 1GiB, and second as the main VRAM on their graphics cards (and since the first generation of HBM only goes up to 4GiB, that will be the maximum the 3xx Graphics cards will have as VRAM)

Intel is probably also checking into stacked RAM technology (possibly Hybrid Memory Cube, HMC, instead of HBM), as it is both cheaper and more efficient as embedded DRAM (eDRAM) for use in their IRIS Graphics chips.

 Hard to say actually. Probably the x86 CPU would be slighly faster on AMD's side (especially when having to do floating point operations, which are a general weakness of the ARM design) while the X1 has more graphics cores and thus most probably somewhat faster graphics.

How big the differences are in real life however is something nobody will be totally able to tell you unless they would be running the same software benchmarking parcours, which is difficult to do since they use a different architecture.

Well, we at least can be sure that it will be more powerful than the Vita. The question is how much. If you want power right now, we are talking about Tegra. However, both Tegra 4 and K1 were mostly seen at tablets, that can support a higher TDP without problems (bigger battery, better thermal dissipation). Tegra X1 is only avaiable now on a mini console, that can, again, support an even higher TDP.

In early 2017, the most performance oriented SoCs will be considerably ahead of PS360, maybe even at Wii U's level (but with a weaker GPU most likely). However, these SoCs will be on tablets and not phones, something that is the equivalent of a portable. If Nintendo went "the power route", they would probably end up with a mid road between PS360 and the Wii U. However, it's necessary to analyse Nintendo's past handhelds. DS was equivalent to a N64, while the PSP was more close to a PS2. 3DS is more akin to GC and Wii, while Vita comes close to the PS3. With that logic, a handheld that was a tiny bity better than a PS3 is the most likely scenario.

However, I fear that the Nintendo strategy of releasing underpowered handhelds and trust on Pokemon to move it forward may be doomed. I don't think the SHIELD console will be anything better than a resounding flop, but they actually managed to get big games like Crysis, RE and Metal Gear Rising ported over. Nintendo could end up with a handheld that would be onslaughted in power by Android devices and their over-reliance on Pokemon and their big IPs could be a problem when, instead of competing against Candy Crush and Clash of Clans, people start to get GTA and CoD on their phones with a decent controller add-on. Everybody needs a phone, why waste money with a handheld that is obliterated by the device you already have?

I didn't had all those grim prospects about handhelds, but now the dam may be well open and if 3rd parties jump the bandwagon handhelds will be done. Home consoles will be safe, if they keep the PS3/4 and 360/X1 strategy: pack as much power as you can because they can run on 150w instead of 10w like a tablet. When the technological advances actually make tablets catch up, 6 or 7 years already passed and you already have a new, beefier console. It's clear now that Tegra X1 still is playing catch-up with PS360 and is almost there, but who cares? Now we have our PS4s and X1s. 5 or 6 years down the road, mobile devices will be on PS4 and X1 heels, but everyone will have eyes only for the already released PS5 Xwhatever. And the cycle goes on.

Probably not and maybe they never will. Cache, EDRAM and any kind of embedded memory uses space on your SoC/APU. The more you put, the less space you have to fit the other components of the CPU/GPU. So when you create a chip that's way smaller than a desktop/laptop one and still has to put x264 decoders, radio signal processors and other things, space becomes precious.

I did some research on this the 3DS apparently does have eDRAM ... (30-50GB/sec supposedly) ... the original model had 6MB eDRAM (VRAM) and the New 3DS bumps it even further to 10MB eDRAM, which is the same number as the XBox 360. Not sure if that's conventional eDRAM or not, but it's there apparently.