This.  MS wants to go on about "But Ryse is the best graphicz".  Whatever.  But is there anything special about XBone enabling that?  No.

There is zero technical impediment to porting any XBone game to PS4, where it would have more power to look/play even better.

So MS' stance is "buy our stuff because we use our millions to prevent good stuff from being more freely available".  What a sales pitch.

Yeah, I noticed that, too. I confess, my first reading of Todd's statement is that it's a production bottleneck, but after a moment of thinking I changed my mind.

It boils down to this. An ERAM machine has to take memory off the main RAM pool and put it on the ERAM before it can be used. I don't know computer architecture enough to know if that's processing the information twice  or not, but it at least has to go through the information once before it can even be used.

A unified memory pool can just call the information as needed. 

For that reason, if the RAM pool has comparable speeds to the ERAM, the one with the unified pool will not only be easier to develop for, but it will actually be faster because it has fewer operations to make and is not continuously wasting operations flipping information in and out of the ERAM pool.

Now I could be wrong. All these units have APU's, so it's not likely that the X1 is burning any of it's GPU's processor doing any ESRAM flipping. It's likely that the power lost is actually going to come out of enemy AI or another background operation, and not the graphics.

I actually don't think Ryse is that impressive. People compare it with Killzone, but you are comparing a 1080p 60fps game with a 900p 30fps one. If KZ had the double of time to render the picture and more than 33% less pixels to output, people wouldn't even dream to discuss the final result.

And remember that MS said that it "discovered" that reverse transfer of info was "free" only late in development, so Move Engines that handle memory loads/unloads are not designed with that workload in mind.  This is besides the fact that the quoted ESRAM max bandwidth only applies if both directions of transfer are maxed out.  You can write a test program to do that easily enough, but in an actual game, there will often not be any use value to using the reverse direction fully, so that theoretical bandwidth just isn't helpful, in addition to the impediments to actually reaching that theoretical peak.  XBone devs have an extra restriction on their work, that they need to optimize everything around the ESRAM, yet doing so doesn't achieve any real benefit vs. PS4 whose GDDR can do the same thing without jumping thru hoops (32MB sized hoops).  PS4 devs can also consider other approaches to graphics that simply wouldn't be compatable with 32MB ESRAM limitations.

Your second point is missing a major thing: XBone's ESRAM is PHYSICALLY displacing GPU cores, it takes up die space that Sony uses for 50% more GPU cores.  That is the power loss, because the power JUST ISN'T THERE in XBone.  What that power is used for is up to the dev, PS4 has alot more flexibility because it has like 8x the number of GPGPU threads that let the GPU be used for standard graphics, physics, sound raycasting, even AI.  That can use aspects of GPU cores that are temporarily not used by their graphics function, or actually take over a core from graphics functions.  (An interesting use is using GPGPU to more efficiently achieve graphics than standard shader models allow)

In the MS voodoo laboratory, as noone ever was able to explain the numbers. Let's bring some points up to clear up stuff and obfuscate clear stuff:

1. There is a poster here who bravely states "esram is only a bottleneck if it is used"

Fact: That is a funny idea because what happens if you DON't use the esram? That is prety easy to figure out: the gpu and the cpu and the dma engines all access the main ddr3 dram. Since the ddr3 has a 256bit interface, only one of the 256bit dma/memory controlers can access the main memory. This gives us 953MHz*256bit = roughly 25GByte/s bandwidth for the gpu. Good luck making a game that does more than 10fps at any resolution...

2. There is a number of 204GB/s (which would correctly be 218GB/s after the clock uptick) for esram and real measured 145GB/s bandwidth number stated by unknown testers under unknown conditions.

Fact: The first number is complete and utter bullshit. This bogus number comes from a pr/tech guy who is frequently quoted by journalists as "we can read and write at the same time into the esram". No vlsi engineer has ever come forward to explain the number and how that actually works, and unless the layout of the mmu crossbridg in the apu is considerable more complex (and I mean considerably more complex) than anything ever done before (this includes supercomputer mmus), I stand by my bullshit meter hitting the fan. The second number, 145GB/s, on the other hand, is completely believable, though. However, this number does not come from the gpu data side. It is the bandwidth reached in the mmu crossbar switch. It is achieved when the gpu accesses the esram at 109GB/s (by either reading and/or writing to the four individual 256bit memory controllers of the four separate 8MB esram blocks) and simultaneous access (parallel in the mmu crossbar) of the cpu mmu of the ddr3 main ram. This gives us 109GB/s + 40GB/s = 149GB/s data rate (or 177GB/s if the cpu could use the full bandwidth (cpu access is stated lower by ms).

Again the memory layout of the XBox One apu is extremely complicated (it can get a lot, really a lot, more complicated when the gpu accesses esram blocks and ddr3 at the same time, concurrently with a dme engine accessing esram, and cpu concurrently accessing the ddr3 ram. That would probably be the messiest access pattern I see in the XBox One, but it would get the number upto (109+68) = 177GB/s, the maximum memory thorughput possible (unless there IS novel voodoo technology inside the apu).

I actually don't think Ryse is that impressive. People compare it with Killzone, but you are comparing a 1080p 60fps game with a 900p 30fps one. If KZ had the double of time to render the picture and more than 33% less pixels to output, people wouldn't even dream to discuss the final result.

It's not much of a stretch to say that the ugly reality is that Ryse would run much better on the PS4 (higher frame rates) while looking the same (albeit at a higher resolution). 

The hardware architectures are so similar (with better GPU and faster memory bandwidth on the PS4) that it's not even a hypothetical "what if?"

BINGO!

Because the PS4 uses 8gb of unified GDDR ram there is no need to copy or send stuff to another ram like X1. Once optimised and mastered the PS4 will be untouchable by the media box. GDDR5 can read and write in one clock cycle. So just imagine in the future When developers have mastered GPGPU compute and the advantages of the PS4 setup and memory??? Epic meltdowns will ensue!