Hoping Ryzen 9 3900X goes back in stock soon. I can't wait to get one.

I have a Ryzen 2700u notebook and whilst the CPU performance is adequate for the price point... It leaves much to be desired on the battery front, the 12nm revision aka. the 3700u was only a marginal improvement.

The GPU side of the equation is a little more interesting, the IGP is bandwidth starved, dual-channel DDR4 2400mhz isn't doing their mobile graphics any favors... But it's also TDP limited, if I hold back clockspeeds for the CPU to 70%, the graphics will clock higher resulting in higher gaming performance... The APU's just don't prioritize what parts of the chips should take priority when it comes to gaming properly.

Plus the 2500u with it's lower CU count without tweaking can offer more gaming performance than the 2700u as well in some gaming situations, due to the same TDP reasons. - They have the same TDP, but because the 2500u has less transistors being pushed thanks to a lower CU count, it can spend more TDP dialing up clockrates instead.

AMD's mobile efforts have always been a little hit and miss, hopefully with Zen 2 in notebooks things improve.

Will AMD take the chiplet approach with APU's in Notebooks with Zen2? Who knows. I won't say "no" to a 6-8 core Zen2 APU in notebooks @15w TDP, that will be a worthy upgrade unlike the 3700u.
If AMD takes a chiplet approach it will be interesting to see if the GPU portion will be it's own separate chiplet... In theory that would give AMD more flexibility to mix and match GPU's. Or if it will be part of the CPU cluster or the I/O die/s.

Great this will work fine in my next Xbox

I like lamen.

@Pemalite how exactly do they measure eficiency of the architeture? flops/watt? time to execute instructions/flop?

By the amount of work over a period of time compared against total power consumption of the chip.

Flops isn't really used because it's an entirely theoretical number... And is only one part of a processor, it completely ignores things like Integers which are extremely  important for some workloads.
Any decent outlet will run a series of benchmarks like Cinebench, GIMP, Dolphin 5.0 render test, Handbrake, Ashes of the Singularity game etc' and grab performance and power consumption metrics.

Ryzen is efficient because the Ryzen 9 3700X can match the Core i9 9900K in the majority of benchmarks... But does so with much less power consumed.

Understood, so at least one of my hypothesis made sense.

There are many Zen 2 'SKUs' so not sure what the "full fledged" parts are but it's sounds more like console manufacturers are getting 8 cores clocked at 3GHz+ ... 

A variety of leaks for both the Playstation 5 and Xbox Scarlett have positioned the next gen consoles with low base-clocks of around 1.6Ghz, but high 3ghz+  boost-clocks.
So it would be safe to assume games that aren't pegging the TDP of the GPU will likely see CPU clockrates ramp up to eat into the TDP limit and hit sustained boost CPU clocks, much like what we see with Ryzen mobile APU's... And vice-versa.

But even an 8 Core Zen 2 @1.6Ghz will shit all over an 8-core Jaguar at 2.4ghz anyway...

Of course, salts and grains and all that.

The question to me is more on how it will be designed. Will it also be with an I/O chip and CPU chiplets like the Ryzen and Epyc chips or will it be build differently? How much cache will the versions in Xbox and Playstation have? What memory will it support? will it have SMT enabled or disabled?

For the record, I'm expecting 8 cores at 3.2-3.35 Ghz. Efficiency tests showed that until then the power consumption was very low (below 50W) but rose pretty fast after that point. And the difference between 2.6 Ghz and 3.2 Ghz was only 5 W. Since this includes the I/O chip, which is the same chip as the X570 chipset, one can assume that one alone pulls about 10W just like it does as the X570 Chipset, so the CPU part would only be at 40W maximum at those clock speeds without any need for binning. I'm certain it will clock lower in some instances, but since the clock speed below 3.2 Ghz doesn't have much effect on it's consumption, I doubt it will be used much except when idling.

As for the GPU, I expect something similar to the RX 5700, although not the same chip. I'm expecting more like 44CU with 2-4 CU deactivated for enhanced yields, and clocked a bit slower than he RX 5700 (somewhere about 1400-1550 Mhz) to limit power consumption to something a console case can dissipate without overheating (which is normally around or slightly above 200 W).