I am not completely tech savy, but is there not a presedent for a portable device requiring far less power because it only needs to output at a fraction of the resolution? Sony pantented some tech eons ago that allows resizing of images at minimal loss of quality. Also, Many multiplat games are being proven to run on Switch, that means that they can run in some depowered state on a portable device. 

Game Developers are already used to scaling for refined hardware teirs now. PS4 Pro/Xbox One X ensured that.

Sony also just patented some kind of DRM tech.... How relevant that is is yet to be seen. Yet there are already president for allotting digital versions for consumers who own a physical copy. Look no further than Xbox's backwards compatibility. Not to mention.....I don't think they would see it at "leaving owners left out". Digital is the future anyway, and is very much accepted in the portable space. Look at sell phones, look at the Vita. When it comes to portability it can easily become the preferred method.

If Sony wants to continue to grow their OS, Software, Service, and Store, they will definitly need to expand the form factors these are available on. It is very possible that they could release a Mobile PS4 on the 7nm fabrication process, if they put a lot of effort into making the PS4 tech more power freindly with this revision.

If 7nm is ready for mass market by the end of the year, Sony could drop a PS4 Super Slim (Digital Only Set Top Box) and PS4 Mobile on the same chipset. This would allow them to sell the SS for $199.99 or even $149.99 giving them a great entry device for PS4 Games, and PS Vue. The PS4M could hit at $299.99, and offer full PS4 support for all games, software, and services, including PSVR.

I don't know whether they will go this direction, but both of these products are very possible within the next 6 - 12 months. I have said it for a long time, but Sony seriously needs to dump Xperia, and roll Sony Mobile Communications into Sony Interactive Entertainment. They are only selling 10 Million Xperia's over a dozen different sku's, and loosing money hand over fist. Moving to a shared hardware, shared software ecosystem, running on their own OS would be a massive boost, and give a very positive outlook for the future of the comapny. They would make 100's of millions more selling a single PS4 Mobile model backed by their own OS, Sofwatre, and services, even if they sell half the amount of units.

Hopefully the talk of future 5G products, and new 7nm gaming chips from TSMC is in fact pointing to a return of Mobile gaming for PlayStation.

A 1.84TF portable? Nope.

The technology just isn't there, and even though the Jaguar is crap, good luck getting an x86 processor in a portable that can match it.

A PS4 level device in a form factor like the Switch just won't be possible until maybe 2021/2022.

A PS4 Portable while possible, does seem kind of unlikely. When PS said they had to pay attention to Switch, I don't think they necessarily meant they need to build one. Trying to out-price it like they did with XB1 would make just about as much sense as trying to create a mobile PS4.

Yes, some gamers want the mobility, but there are plenty of others who simply require a cheaper stationary PS4 to be able to enter the ecosystem. Like some others have said, the cost and size at this point in time would most likely be a problem, unless PS wants to just get anything out on the market and is also willing to subsidize it.

What would be more likely, would be a PS4 super slim and Pro slim. It's been two years already since PS4 slim and Pro launched, and if super slim and Pro slim launched this holiday, then if PS5 didn't launch until late 2020, you could possibly end up with a PS4 super duper slim or Pro super slim late 2020 as well for super cheap, maybe. If PS5 is launching late 2019, then getting the PS4 super slim and Pro slim out now would almost be vital.

The one way I can see a PS4 Portable launching this holiday, is if PS and Nvidia have been working together for some time and have a custom Tegra of their own. Getting third parties to port to Switch hasn't exactly been easy, but if PS has an extremely similar device, then that very well may change things. While I also think this is unlikely, both PS4 and XB1 ended up with very similar hardware in the dedicated home console space, so who's to say that PS and Nin couldn't on the handheld hybrid end?

There is the slightest possibility that AMD has an ARM based APU they've been working on for PS, but I would say that's much less likely than Nvidia getting PS on board with Tegra. Otherwise a 7nm Ryzen based APU that's BC with PS4 games should definitely work for a portable, but that wouldn't be until late 2019 at the earliest due to manufacturing process yields/cost.

it's ok to not be that tech savy, but rather than throwing out assumptions like this it would be good to ask more tech savy people why such thing hasn't happened.

i think a few users, including myself, have presented several reasons why such a thing isn't even in the reals of what's possible.

it's ok to dream, but I wouldn't call this either a theory or a prediction :)

I don't think a digital only PS4 Mobile would cut into the potential market as much as you think. Digital is growing stronger and stronger, and this would be a perfect device, to drive even more people to buy digital. Even if they don't buy a PS4M, just knowing that a digital copy could be played on PS4M if they decide to buy in the future would easily tip the scales. 

The demograohic question is always asked for new products. Many people asked, who the Switch was for. People asked why they would ever need a cell phone to do anything but make calls, and who would want something like that. Before the start of this gen, many were asking who needs a console in this day and age. There are some ~250 million people that by consoles and handhelds. If a console or portable is released that meets peoples needs it will sell.

Going on to price, I don't know how to say it, but there is no way a PS4 Mobile would be $400 - $500. If it is based on the OG PS4, and running on the same chipset as a theoretical PS4 SS, then there is no reason it should be more than $299.99. Smartphones massive mark ups have blinded people to the true cost of mobile devices. A Smartphone cost $250 in parts and sells for $800 - $1000, a portable cost $250 in parts and it is $200 - $300. In the console business it has never been about soaking consumers as much as possible on hardware, you sell at cost and make money on software and services. 

Are there a plethora of new consumers yet to by PS4? Did PS2 sell 150 million units? Did PS1 sell 100M+? Did DS sell 150M units? There is plenty of room for PS4 to grow. There is no reason that PS4 spanning Home and Mobile could not be the most successful gaming platform of all time. On the flip side, there is no garentee of it either. In theory, having a unified platform, that spans across mobile and home should reach a larger userbase than a platform locked to either one. 

Finally addressing Nintendo. What makes a PS4 Mobile different, is the shared ecosystem. Sony would not be building an entirely new product and platform. They would simply be expanding their exsisting Hardware, OS, Software, and Services to a new form factor. Thanks to the shared R&D and Devleopment, a Mobile PS4 would be a very cheap venture for Sony, meaning that they don't have a lot to loose. A PS4 sold is a PS4 Sold, a PS4 Mobile sold is a PS4 sold. It all goes towards growing the same ecosystem. They don't have to sell more PS4M than Switches for PS4M to succeed. If the combonation of PS4+PS4M is more than Switch great for Sony, but at nearly 80M strong already and closing in on $2 Billion in yearly profits PS4 is already a successful platform. So PS4M can sell 2 Million additional PS4's a year or 20 Million. At the end of the day it grows the PS4 platform, brings more people to Sony's OS, and/or keeps current customers active on PlayStation more often. It is a win, win situation for Sony, and increases the value of their OS, Software, and Services.

https://www.amazon.com/Dell-XPS-InfinityEdge-Anti-Reflective-Thunderbolt/dp/B07BWCZD1M
~2.5 TFLOPs on the main GPU, + a little extra (~0.5TFLOPs, if my memory is correct) on the second GPU.
Oh, and the Intel CPU would destroy the PS4, or even the XxX's CPUs.
https://ark.intel.com/products/130411/Intel-Core-i7-8705G-Processor-with-Radeon-RX-Vega-M-GL-graphics-8M-Cache-up-to-4_10-GHz

I could see them releasing an HD streaming device that allows for remote play features to be available at a lower cost than the VITA, that would make sense to me and be forward compatible with the PS5.

An actual handheld though? I doubt it. The VITA tanked and a portable PS4 is not feasibly possible at an acceptable price. It would be little more powerful than the Switch, and most would rather see their focus not split on two platforms.

Will it? Will it really though? Handheld tends to be dominated by Nintendo.

No.

How are you determining power?

False.

Agreed.

False.

 It's not just power consumption, it's thermals, it's price, it's the fact it integrates an entire system on a chip, it's manufacturers working with OEM's... And all of the above.
x86 CAN be competitive with ARM.

False.

Well. You don't have to go Digital only, you can go with ROM/NAND based carts, but you are correct that it would simply be cumbersome to try and force Playstation 4 optical media in the device, thus require the need to purchase a game in a different format.

Then you have the capacity of the storage to worry about, the Playstation 4/Xbox One haven't proven to be exactly conservative when it comes to storage.

Another alternative is to have the disk in the Playstation 4 for authentication purposes whilst you download and play on your mobile device.

There is dynamic resolution, upscaling, downsampling and so on.

Maybe you should try looking past flops?

You also don't require an x86 processor.

Ignoring the $2500 price tag, That is not a handheld form factor.