It is the opposite... there are a lot of changes for memory management on XB1 than PS4.
But let's use some sources just to prove you wrong again...
Cerny said there are three custom thinks that they added to PS4's APU over the actual AMD's APU:
1) An additional bus has been grafted to the GPU, providing a direct link to system memory that bypasses the GPU's caches. This dedicated bus offers "almost 20GB/s" of bandwidth, according to Cerny.
2. The GPU's L2 cache has been enhanced to better support simultaneous use by graphics and compute workloads. Compute-related cache lines are marked as "volatile" and can be written or invalidated selectively.
3. The number of "sources" for GPU compute commands has been increased dramatically. The GCN architecture supports one graphics source and two compute sources, according to Cerny, but the PS4 boosts the number of compute command sources to 64.
2 & 3 are part of GCN 2 standard (PS4 is GCN 1 with added features that AMD used on GCN 2)... it was new on PS4? Yes but every APU launched with GCN 2 has these custom features made by Sony. 1 I will give you that is really something the new APUs doesn't have and maybe they doesn't needs it... a direct bus between CPU and GPU.
These are the Sony changes...
http://techreport.com/news/24725/ps4-architect-discusses-console-custom-amd-processor
Now let's talk about XB1's APU changes:
1) eSRAM, that is probably the big change that makes this APU different from AMD/PS4 APU.
2) DMAs, MS added a lot DMAs to move data between the four elements: CPU, GPU, eSRAM and DDR3... the data can travel simultaneous between them without need CPU resources... these DMAs has secondary functions like data compression/decompression (again without CPU resources needed).
3) Tensilica DSP cores, instead to use the default audio cores found in PS4's APU they choose to made a custom one.
4) Highly customise the command processor on the GPU... it is not like this is new because AMD allow you to create customized command processor for GCN after some version... but they talk in the interview so I put here.
http://www.eurogamer.net/articles/digitalfoundry-the-complete-xbox-one-interview
There is no AMD's APU in the market like the XB1's APU because it is heavy customized from it "standard".
While there are APUs exactly the PS4's APU in the market with less processing units because it is the AMD "standard".
The XB1 GPU is far closer to a standard GCN part than the PS4 is. There's alot more instructions for memory management on PS4 compared to PC/XB1 GCN, there's far more ACE queues, and overall alot more control over the granularity in the PS4 which then got implemented into Polaris and future archs.
While AMD used the changes in PS4's APU for GCN 2 (that is two versions before Polaris GCN 4) the PS4's APU was still the same standard layout of AMD's APUs... no drastic changes with only added features to actual processor inside it... these added feature was used in GCN 2 by own AMD and all the APUs that come after that.
XB1 customizations not followed the AMD's standard layout... the opposite MS and AMD strong customized XB1's APU adding a lot of new processor units (4x DMA, DPS, etc)... just the eSRAM and memory controller to support it was a bigger change than anything Sony did with PS4's APU.
You can't and you will never see on PC market an APU as XB1's APU because it is not standard for AMD.
Since release of the two consoles we know:
- PS4's APU: simple, cheaper and stronger.
- XB1's APU: complex, expensive and weaker.
XB1's APU is complex and expensive because rely in too many customizations... and it is weaker because they needed space on the chip for these customizations and this space was a trade off by GPU units.