That is an assertion.
We don't know if nVidia had any surplus stock.

But we do know they are fabricating more chips to meet Nintendo's needs.

And you have  no proof for any of that either.

From a fabrication standpoint, The Tegra Pascal would be cheaper to manufacture, that's a blatant fact.

Here is another reference point where we are at miniaturization of PS4 performance:

https://www.techradar.com/reviews/intel-hades-canyon-nuc

View on YouTube

The new Intel NUC seems to be a bit faster than a standard PS4, but

• it still needs up to 65 Watt
• the box is still bigger than a comfortable handheld size
• the power brick is external and the NUC doesn't include a battery or display
• it weights 2 pounds
• it costs $1000 (plus the costs for storage, memory and OS)

So don't expect a handheld with PS4 performance for less than $500 next year.

* CPU is several multiples faster.
* GPU is significantly faster.
* Storage is significantly faster.

Ryzen mobile is probably the best representation of what to expect out of AMD's current technology.

And that is 12-25w TDP.
https://en.wikipedia.org/wiki/List_of_AMD_accelerated_processing_unit_microprocessors#%22Raven_Ridge%22_(2017)

It's also only 210mm2 die size, so it's not super super super cheap like with some ARM SoC's, but it's also not stupidly expensive.

Now this is some good conversation on the topic.

A couple more things to take into consideration.

1. The NUC is likely based on a diferent pricing model than a PS4 Portable. Retail price is most likely somewhere between 2x - 3x the cost of components, packaging, and shipping. Teardowns in the months to come will give a clearer picture.

2. The NUC has about 14 additional ports that would not be necissary on a PS4 Portable. PS4 Portable should only require a USB-C port, a Micro SD Slot, and a Nano Sim Slot. Maybe a Headphone jack.

3. The Ryzen Mobile information in Permalite's link are for Raven Ridge, which is 14nm. PS4 Portable would have to be based on 7nm which see improved performance and TDP, along with a smaller die, and more cost reduction. It is the best indication of where we sit with AMD based X86 and Radeon tech for a mobile platform. 

We are closer to a PS4 Portable than some here are thinking. I see a lot of people looking at current desktop components as a barometer, but the PS4 does not use desktop parts. I also see people saying that PSP and PS Vita fell short of PS2 and PS3. You have to remember PS2 and PS3 were much different beasts than PS4. PS2 and PS3 went toe to toe with high end PC's on release. PS4 was using a weak mobile CPU and a mid range GPU on release. 

It really is not a question of tech and pricing, but whether Sony will pull the trigger. Do they want to strengthen their position in the market, or do they sit on a single golden goose and prey the market never changes? I hope they take advantage of this current position, and expand the business, so they can be more flexable, depeneding on where technology takes us.

The 2500U uses like ~25-26 watts in laptop systems, when playing games.

If it was die-shrunk to 7nm, and ran PS4 games at 720p, do you think it would be able to do so?
And would people want a portable that played PS4 games @720p?

https://www.techpowerup.com/242148/globalfoundries-7-nm-to-enable-up-to-2-7x-smaller-dies-5-ghz-cpus

"While a move from 14 nm to 7 nm was expected to provide, at the very best, a halving in the actual size of a chip manufactured in 7 nm compared to 14 nm, Gary Patton is now saying that the are should actually be reduced by up to 2.7 times the original size. To put that into perspective, AMD's 1000 series processors on the Zeppelin die and 14 nm process, which come in at 213 mm² for the full, 8-core design, could be brought down to just 80 mm² instead."

A 70-80 mm² 2500U inside a portable *might* be able to run PS4 games (8threads ~1.2 Tflops) at 720p.
Not sure what memory solution would be possible, to allow this though (but again if your running 720p instead of 1080p, memory bandwidth usage isnt nearly as high).
 

I don't even know if it's possible to make a ps4 portable at this point if you don't want to make it cost a $1000.

Chip companies like Intel, AMD, nVidia and so on tend to try to go for 60% profit margin at a minimum. Ironically... That was also the rough profit margin on Ryzen which has pushed AMD into the green.

Now semi-custom designs like what is featured in consoles tends to have a different pricing model thanks to various agreements.

Hence why I stipulated AMD's "current" technology. ;)

In multiple different aspects, mobile technology has even surpassed the Playstation 4, especially in regards to the CPU.

I dunno... Is a Playstation 4 portable possible right now? Shit yes.
Is a Playstation 4 portable affordable right now? That's up for debate.

I think you are missing the point. The 2500U's CPU is still vastly superior to what is in the Playstation 4. It can be scaled back farther.

Plus the TDP is configurable, it can come under 25-26w, OEM's can implement the chip in different ways with different power states and voltage scaling to reduce power consumption. Plus better binning also helps.

Even a drop to "12nm" (If we can call it that) would bring significant gains.

720P needs to die.

Here we go again... You clearly don't understand flops or how it's presented.
The number of flops is irrelevant. I say it again... Irrelevant.

The number of threads is also irrelevant.

The Playstation 4's GPU is old, slow and inefficient.
You do not need the same amount of Bandwidth to achieve the same result.

Except Nvidia won't work on your ps4 portable

I am pretty sure that conversation was talking about the Switch not being the best example of current mobile tech, and why Nintendo went with the Tegra X1 vs the X2. 

That said, there is no need for Nvidia to work on PS4 Portable. AMD has Mobile tech that is perfectly capable of doing the job. Raven Ridge or Ryzen Mobile is already very close on the 14nm fabrication process. With 7nm fabrication coming late 2018 to early 2019, a PS4 Portable will be possible. That is why this topic is being discuessed. 

The 2500U laptops are the closest thing, and those are like 499$-599$.

Im sure you could do a 7nm shunk chip in a handheld and it be much much cheaper.
So a PS4 portable wouldnt need to be that expensive.