PS5 pro maybe?

Probably GDDR6, as it theoretically consumes much less power for the same bandwith compared to GDDR5(X). This leaves quite some more Watts to spend on other things like CPU or GPU

Yeah what are the chances the ps5 will have it? 

Not so fast.

Even if DDR5 is ready by 2019, it's implementation into actual hardware will take longer. I don't expect an APU with DDR5 support before 2021 earliest. Even then, they will have to ramp up their RAM controllers. The 25.6 GB/s is with DDR4-3200, which AMD doesn't support yet (DDR4-2666 is officially the maximum, some DDR4-3200 do work, but not all). I do expect AMD to continue rising their support for DDR4, with the Zen 2 in the Raven Ridge successor finally reaching DDR4-3200 officially and DDR4-3600 in the subsequent one. Even then, in dual channel we're still below 60GB/s, which is barely enough for 16 CUs maximum without starving them to death with the low bandwith. There's a reason why the APUs stayed at 8 CUs for so long and only going up to 10 with Raven Ridge now.

DDR5 won't start with that speed. Just like DDR4 starts off at 1866, I expect DDR5 to start off as low as 4000 or even just 3600 while it would need 6400 for the 51.2GB/s per channel. So it will take a while until that bandwith is actually available for APUs, and by that time their power compared to high-end GPUs won't budge very much - it might even drop even further down the line depending on how fast the top of the line evolves.

This is funny, but I seriously thought you were talking about Dance Dance Revolution 5...

anyone else...?

nobody?

... I'll see myself out...

My line of thinking is the test units they would have now would either be using DDR3 or 4.
They would probably be using a pool for OS tasks and to improve data streaming from storage.

I did say that there is only a chance for them to use DDR5 if the next gen consoles release later than we think.
If anything it would be more of late revision, like how the PS4 jumped from 4GB of GDDR5 to 8GB, though in that case it would require a bit more work.

My guess is that the next generation will focus heavily on data streaming, and will come with an SSD, if only to be used to cache data.
I don't think we will see 64GB of RAM on the next systems.
It is much cheaper to have developers implement data streaming from an SSD into a 16 or 24GB pool of RAM.

Sure. And Erdogan is a democrat.

Next gen will have 128GB of RAM, a 16x increase just like we have seen in every generation since PlayStation. PS5 will likely have 96GB of GDDR and 32GB of DDR. Anything less would be a PS4 iteration. Otherwise the console industry becomes the cell phone industy, dropping new numbered units without any significant improvement over the last model. 

Not to mention the increase in chip densities. Which will be important if you want to aim for 16GB/24GB/32GB of DRAM in the next gen and still be affordable.

You are only comparing raw bandwidth. Which is going to be inaccurate.

nVidia and AMD are constantly inventing new technologies to save bandwidth you know with various forms of culling and compression.
So your "16 CU Maximum" claim is without basis.

The main limiter for why APU CU counts haven't exploded is entirely down to costs... AMD typically reserves roughly 50% or more of the die space on an APU... Entirely to the GPU. And that's with current CU counts on chips like Kaveri with up-to 8 CU's. 8.

People made similar ludicrous claims with the Playstation 4 Pro, Nintendo Switch and heck even Scorpio before release...

In the end, it all comes down to costs and the available technology.
There is only so much hardware you can throw into a box that fits into the $400-$500 price bracket. Which means 128GB of Ram when memory densities haven't increased at the same rate at the same price points? Ain't going to happen.

PS1: 3MB Ram. (2MB Main, 1MB video)
PS2: 40MB Ram. (32MB System, 4Mb Graphics, 2MB Audio, 2MB I/O.)
PS3: 512MB Ram. (256MB System, 256MB Graphics)
PS4 8448/9216MB (Pro) Ram. (8192MB System + 256MB/1024MB Background/OS)

PS1 to PS2 = 13.33x increase in Ram.
PS2 to PS3 = 12.8x increase in Ram.
PS3 to PS4 = 16.5x increase in Ram.
PS3 to PS4 Pro = 18x increase in Ram.

Other than the jump between the PS3 and base PS4... Your statement does not hold true. (Even then you are slightly off.)
And the only reason why the PS3 to PS4 jump was so impressive was because it was an extended console generation.

People also said PS4 would only have 3 or 4GB of RAM, and most thought 8GB was outlandish if you were predicting that. And as far as increases in memory density goes, I keep reading articles that we are going to see massive leaps in memory and storage tech over the next couple of years, which should lead to much more RAM than people are expecting, and SSD storage.

As for the increases, it is closer to 14x every gen on average, with last gen seeing the biggest increase yet. Yes, it is due to the longest gen so far, but I see no reason why this gen won't be just as long. I don't see PS5 happening until 2020 or even 2022, as I don't see the technology to warrent that leap until then. A PS4 Premium makes more since in 2018 or 2019, followed by a true generational leap when the tech is ready.

I believe PS5 will be an 8K console to push 8K TV which is going to start to get a huge push over the next few years. It will also need to support 4K per eye VR. Both of these will require this much larger GDDR RAM pool. The DDR RAM pool will need to be massive as well, as PS5 will continue to push content creation, and allow much more multitasking, with stuff like video editing being possible at all times.