I don´t pretend to be precise here, but the last 2 PS have had hardware with the performance of a mid range PC when they lauched. It would be the same thing as saying hardware that can be compared with 3 year old high end PCs. So if GPU releases don´t take longer than before and AMD is the supplier and AMD can reduce power consumption (too many ands) We can spect AMD VEGA performance by 2020. That´s 10-13 teraflops with enough bandwith to fill those GPU pipelines.
High end Gaming Rigs have 16 GB of RAM and 8 GB of dedicated graphic card memory. That would be 24 GB of RAM. I hope PS5 would have that amount, but they may reduce costs and go for 16.
Let see game´s VRAM requirement acording to guru3d.com game reviews
Ultra HD resolution (4k)
Destiny: 3300 MB
Battlefront 2: 5200 MB Ultra quality
Wolfenstein 2: up to 6400 MB with Vulcan 1080 ti
COD WWII: 7400 MB
Shadows of war: 9300 MB with ultra textures.
Ghost Recon wildlands: 6300 MB

So with the exception of ME Sow, 8 GB Graphic ram is enough for today high end ultra quality 4k.
Some games need 16 GB of system memory, many run with 8. So probably console developers can go with unified memory architecture and optimize for 16 GB. That is one console optimization you can have and developers love it. I would love 24 or 32, but we´ll see.

Of course I would love a giant leap in a gen, with bigger worlds, more NPCs, 32 or 64 GB of RAM, 20 Teraflops and so on. But I don´t think sony would take the risk lauching a third PS4. They would go for PS5 and PS5 pro instead.
As long as they put a good CPU inside replacing the old jaguar cores by Ryzen cores, they can make PS5 upgrades with more ram and a better GPU lauching a pro or a ultra version of PS5 later.

Also we have to think if its going to include a blue ray 4k player or not. That would increase the size of games (phisical) and size of storage is still a factor for a true generational leap.
2 TB disk drive would be a nice place to start.
So I´ll be ok if PS5 is at least
12 Teraflops GPU.
24 GB of RAM min.
Ryzen CPU
4K blue ray
Don´t know if that would be a gen leap, but at least better than vanilla ps4.

I have a question, People say the Xbox one X is in the middle of this generation and the next. If the PS5 is going to be at least 2x better than the xbox one x what's going to be the price? the X is 499$ and i guess microsoft is selling at cost or even at loss so it's impossible to have a better Machine in 2 years at 399$

2022. PS4 will be selling so well into the coming years. PS5 will come if their is a specific point in technology like good VR.

shrinks in processes reduce price of components. More CPUs or GPUs are obtained in one waffer. (imagine a pizza being cut in smaller pieces, you get more smaller pieces for the same price of 1 pizza). So CPU and GPU will be cheaper. Same with memory. You are right, you can have 2 times or more CPU peformance, Im not sure we would have 2 times the RAM (24 GB). I hope so.  So I wish they can make a 2x better console for 450-500 in 3 years. If they don´t do at least that, It won´t look as a new gen at all. At least It should be native 4k mantaining today´s quality. 

If you think about the new standar Xbox One, is 1.4 teraflops. And sometimes struggles to get to FULL HD. 

The one X is for 4k gaming, It needs 4 time the pixel throughput and for that 4 times the flops with according memory feed. 

1.4 x 4 =  5,6 Teraflops. And that´s why One X is 6 TF.  And it struggles to run 4k natively.

A 8 Teraflop PS4 would be the same PS4 but at native 4k. 

I hope they can make a 10-13 Teraflop machine cause I don´t want the same of what I have but at 4k. I would like real better graphics and not only a jump in resolution.  But more power comes with more expensive cooling, larger case and so on. 

Also 24 GB would be nice for at least pc like ultra quality. But they might go for unified 16GB for cost reasons. 

Anyway. I guess Sony learnt from the past and doesn´t launch a 600 USS machine. People would say its too expensive, no matter if its a real true next gen. Thats the problem. I would love to pay that for a true next gen manchine, but im the exception. Most people would prefer a struggling PS4 that gives you the same but at 4k paying 400. 

It would be a good thing if they can make a 450-500 USS  machine that is 2x Xbox one X. 

Yep, fits my personal assumption as well. Everything above just sounds unrealistic. I’m sure they’ll go for a 400,- price again. UHD BluRay as data source seems a given imho. They can’t make people download 100-150 GB games.

I don’t know....we all would have said you’re crazy if you’d have told us the PS4 would have 8GB of GDDR RAM for 399,- back then.

Thanks for the info so a 399$ PS5 would be reasonable mid 2021

False.
The Playstation 4/Pro has 5/5.5GB.

And 8GB is less than the Xbox One X for games. - So you are basically asserting that the Playstation 5 will have at-least one aspect that is inferior to the Xbox One X. - Do you understand how silly that nonsensical position is? Especially as it's launching years from now?

Maybe because the Xbox One X lacks in other areas that prevents it from hitting Full HD? It's not just the fault of "flops" you know.

No. It is 6 Teraflops because that is what was economically feasible for the price point Microsoft wished to hit with the available technology.

No.

You are still clinging to the false idea that all there is to a processor is flops.
Guess what? There isn't.

You can have an 8 Teraflop GPU provide BETTER graphics and MORE performance than a 10 teraflop GPU.

Not next gen it won't. 24GB is already starting to trickle down into the mid-range on PC. (I.E. 16GB system Ram + 8GB video Ram)

Ram also doesn't feature any processing components... Thus, if you have something compute intensive, but is lax on ram, then having 1024 Gigabytes of HBM3 will make zero difference.

Sony is going to want the PS5 is stay competitively priced, $400 - $450. And you can't say the One X runs it's games in native 4K because it doesn't. There's a few, but the majority don't. I'm fine with checker board 4K being upscaled from 1800p (or what ever it'd be) on the PS5. Remember: performance.

Even on PC with max settings it is impossible not to have lower textures detail. It is same with every game. Some levels or parts have really good textures and some part or level have lower texture detail. If someone really looks for it or zoom you can easily find it. 32gb sounds great but probably 24 is more than enough with at least 16 reserved for games