256-bit bus would not be enough for native 4k resolution if we wanna have a decent graphic improvement. It's almost certain Sony and Microsoft will go for 14Gbps pins giving 448 GB/s memory bandwidth for 256-bit bus and shared with the CPU about 400 GB/s is left for the GPU. So that's why I was concerned.

About the performance, I don't know why you always yapping about TF performance, it's irrelevant unless Navi will be a major redesign which I seen you don't believe, we can guess that hopefully Navi will bring upwards 20% performance per/TF improvement compared to VEGA. And I expect Navi will be in both Sony and Microsoft consoles.

I don't know why you altered my last quote, but 4K is already happening on Xbox one X, take a look at far cry 5, red dead redemption 2 and Fallout 76 they all are native 4K, what PC does it won't matter.

512GB/s should be easily attainable on a 256bit bus by the time 2019 rolls around... Combine that with draw stream rasterization, improved delta colour compression and so on... And you can get allot of mileage out of that 512GB/s of bandwidth.

Keep in mind that the Geforce 1080Ti only has 484GB/s and is rather proficient at 4k. - That is the ballpark of next gen capability in my eyes.

Because people like yourself cling to it.
It's like how "bits" was used to determine console capability once upon a time... And yet the Original Xbox being 32-bit was more capable than the Nintendo 64 being 64-bit.
But tomatoes, potatoes.

Navi is not a major redesign, well. No more than what Polaris or Vega was anyway. AMD have even stated as much as it's still Graphics Core Next based.

20% uplift whilst nothing to sneeze about, is not going to turn AMD's lacklusture GPU position around.

It was a copy-paste.

4k happens sometimes on the Xbox One X. It's not guaranteed.
Many games employ reconstruction techniques to achieve 4k, other games don't hit it at all.. And some games employ a dynamic scaling algorithm where it's only 4k some of the time.
In short... It's not a true 4k console. It's not a native 4k console.
The fact it is capable of outputting some games at that resolution doesn't change that.

But if you don't believe that... Then you are contradicting your prior point in regards to bandwidth/resolution, the Xbox One X has significantly less bandwidth than you listed. (Though raw bandwidth numbers don't tell the whole story anyway.)

PS5 2020 is a lock at this point.

Not gonna happen. 

MS has already outright started talking about next gen with all its scarlet talk. Sony has already planted those seeds too with all that talk about PS4 being at the end of its life and now pulling out of all major media events for at least up until E3 2019. And even admitting that they have nothing to show.

This is not all coincidence.

I have been saying this for a while now, that the next gen consoles availability is tied directly to the availability of 7nm fabrication. All indications points to 7nm chips becoming mainstream in 2019. Which means they will be ready to go into consoles in 2020. Which means that as we are here typing all this those next gen consoles are very near finalized and the only moving targets right now being things like clock speeds and memory and storage quantities.

MS is also probably fully aware of how far along sony is to the next playstation as is sony very aware of MS position too. And its in MS best interes to not allow sony start the next gen conversation again, so I fully expect MS to announce their next gen console first and probably at E3 2019. 

Don,t worry about their respective OS, we are already using them right now. New features will be added to them and they would become more robust but they will both be basedon whatever we are using now. No need to reinvent the wheel when it comes to a consoles OS. Especially now.

To me it also depends a lot on whether or not PS is going to have a large 25th anniversary event later in the year. That alone would be a major obstacle for MS. If PS were to add to that either new IP, $199 PS4 SS, $299 Pro S, PS5, or all of the above, it's going to eclipse Scarlet, unless it's something out of this world that blows up peoples minds and not their wallets.

If I were MS, and I were ready, but knew I had to deal with the PS 25th, I'd steer clear, even if that meant pushing the Scarlet announcement back until the early new year, and a launch by e3 at the latest. If I couldn't make that happen, I'd just give XB1X a full 4 years and try to have a worthy PS5 Pro competitor ready a year in advance for 2021.

The Xbox one X is just a gap-closure console, to bridge the gap between 8. generation and 9. generation consoles. Just like the PS4 pro. Don't mistake them for being the next generation consoles, though they have better hardware specs and are the latest to commercialize. Nintendo is actually also rumored to come out with a revised switch in 2019. 

Besides it is now rumored that MS will release another updated current gen console in 2019, with no Disc.

We are going to hear a lot more next year.

Or make a powerful machine priced around $500-600. While supporting the Xbox One X for around $299 with the same software.

That way MS can still boast about having the most powerful machine on the market and an option an affordable option that plays the same games.

At this point, I think MS could release a great console in 2019. Its evident they learned their lesson when designing the X1S and X1X. When you say OS, I think you mean UI? Either way I like what the X1 has thanks to years of refinement. More powerful hardware will fix sluggishness though.

I think my bigger concern is they would have to make a really expensive console to create something far more capable than the X1X. I mean the X1X already handles modern games with ease in the graphics department thanks to GPU and a big boost in RAM, I'm sure the improved CPU is also making 60 fps more stable. It seems like Ryzen would be perfect for new consoles and are much better for 60 fps. On GPU though, at a minimum I would like a double the GPU power as the X1X, which could be expensive but we need a big jump to justify new hardware.

Essentially, we need a significant specs upgrade but we already had a pretty significant hardware upgrade with the X1X. It could be argued the X1X already has the GPU power of a next gen console yet still not what's needed to make 4K standard. So pushing it to 2020 seems like a good idea just because we don't really need new consoles per se.

Well rumors must be taken as rumor.

I still prefer 2021 as the current games are still great and every year we hold on the next gen, more power and jump we get. But seems like 2020 will be the time for PS5 to release. Let's start to patiently hype the coming.

Definitely there will be cross gen games and the Pro, X will be supported for some more years as well. But once they start making games with ryzen, next gen hardware these console will phase out.