There is a reason why the memory will not sufficiently be used to be worth adding, that being that the supporting hardware does not have the bandwidth to use the ram effectively, the APU does not have the raw power required to drive the data bandwidth needed to make adding additional memory worthwhile, and when your target framebuffer is 1920x1080 or less, theres only so much texture data that can be displayed before adding more resolution to the texture data becomes a waste of bandwidth - sure its nice to have pretty textures that are still pretty when your face is right up against a wall, but no developer is going to waste the system resources to add additional texture detail that for 99% of the time you will not see, for two very good reasons.

1) adding that level of texture quality is extremely costly on the creators side

2) the data thats put into memory needs to first be put in to memory to begin with - assuming they took 4gb of ram of system, and left 8gb for video - even if we assume they used only 2gb of ram for textures, to support these textures you would also need to bump up the lightmaps, bumpmaps and shader quality - resulting much of your memory available being used - AHA! i head you scream, SO IT DOES USE IT ALL!, yes, indeed it would, but then you would need to wait for that data to be loaded from hard disk to memory, or from optical disk to mem, both of which would take a long time - and for the former, it would also mean that games take up a substantially greater amount of hard disk space and given that the xbox one has a fixed, non-swappable hard disk that would be a stupid choice.

But i digress, if any of you would like to point to *ANY* game, mods installed or otherwise on PC that uses more than 4gb of vram at 1080p then I will hold up my hands and say "okay, i might be wrong", but until then, youre just ignoring the reality of the situation.

System memory is used primarilly to load meshes, sound and textures that are not time critical, which are then passed along to the graphics unit to be processed, or placed in vram to be accessed faster when needed, this is an entirely abritrary process however, you can run a modern game on a pc with a decent graphics card with just 2GB of system ram, typically the system ram is used to stream game data from hdd to system ram to speed up load times and provide faster data pool switching but this is primarilly a result of the inefficiencies of a modular system, a closed system like a games console relies much less on this process than you are suggesting, because data can be loaded from fixed media directly into whichever memory pool the program defines - but the end result is the same, even if you split 8gb down the middle, a decent spec PC even with its inefficiences as a platform, with 4gb of video ram and 4gb of system ram, will still run games at 1080p perfectly fine and even then will still NOT FILL UP ALL 4GB OF VRAM.

Even if current engines magically "evolved" as you put it, there is a platau with regards to renderspace and framebuffer bandwidth, a large part of why there is still such a push for faster more powerful graphics cards isnt because engines demand it, its because modern monitors resolutions are getting higher, and with them the power and resources needed to feed that video data requirement grow - people who are still using a 1080p monitor and an old graphics card are still able to play modern games just fine.

But i will say it again

the PS4 and Xbox One, do not have the CPU or GPU power to use more than 6gb of vram effectively at 1080p, if you started pushing more texture data through the framebuffer you would just be deminishing the performance, 12gb of ram would not make the system better, 12gb of ram would impact the framerates in exchange for an extremely minor bump in graphical fidelity.

But i digress, if any of you would like to point to *ANY* game, mods installed or otherwise on PC that uses more than 4gb of vram at 1080p then I will hold up my hands and say "okay, i might be wrong", but until then, youre just ignoring the reality of the situation.

I will say it again: We are not talking about vram here, we are talking about ram in general. Unified ram it is called. It's not all about graphics. And why would ram effect framerates in any way? I sense a lot of misunderstanding here.

And no, engines do not "magically" evolve, they just do. We read several comments from devs already who said that they will adjust and improve their engines for next-gen and this will of course affect PC-games aswell.

Firstly, you are "predicting" the future, not stating fact, thus it should be taken with a grain of salt. - Don't get me wrong, I believe the Xbox One won't be getting a Ram boost anyway. - Edit: I was right from the beginning on the memory upgrade not happening. :P

As for whether the PC will use 4Gb of video memory today or not isn't the point, the point will be what will the video memory requirements be in a couple of years time?

The rest of your points I don't care to argue about, it's mostly opinion not fact and I have more important things to do with my time tonight. :)

I covered the unified memory, you know full well i did, i drew direct comparisons between closed and modular systems

Do you *genuinely* believe that memory usage and framerates have no link what so ever?, increasing memory allows for increased texture, shader and geometrical detail, increasing these impacts GPU performance, conversely framerate as performance drops in response to the increased ladder of processes and job complexity.

Of course, if youre saying "nooo they will just use the ram for store things not process more" then the benefits are minimal, load times are increased as streaming the required data when its needed rather than loading it all in to ram in one go is a much more effective solution.

But, of course, youll completely ignore that and stick with your gun on the "hur dur but its different, it will benefit" because you do not have a background in GPU fabrication and operation.

A prediction based on knowledge, knowledge from my previous employer, which I will cover later on in this post.
There is a direct correlation between the framebuffer size and the relative vram usage, with an equilibrium between performance and video quality, at their current specification that equilibrium sits at around 2.3-3gb vram, 2-2.5gb system ram for current and in-development engines, and for engines which render the scene multiple times and store the data in memory to be combined later into a single frame, 3-5.5gb vram at maximum for the framebuffer, once you pass this equilibrium between performance and memory usage you start impacting framerates in favor of visual quality over performance, adding more ram upsets this equilibrium by increasing the address space and upsetting the way the closed system has been designed to handle that addressable space.

So we can look at this three ways, i will spell it out clean and clear so you can understand each scenario

increased texture, bumpmap, shader, detailmap resolution making use of additional memory:
- higher load on GPU as more data to process
- should other data need to be loaded, current data needs to be purged and new data loaded which results in:
- increased loading times
- Minimal increase in graphical fidelity as target framebuffer resolution limits how much of these higher resolution textures are actually visable.

store more game-data in ram rather than streaming what is needed
- higher load times
- more system resources used on managing the larger memory pool to keep track of resources

using extra memory to handle multiple render stream outputs or using downsampling rendering higher resolutions internally but writing 1080p to FB
- increased CPU overheads which impact GPU functions on APU
- increased resource management results in lower output performance

The only benefit additional ram would give to the system would be for background services and OS-level functions such as increasing how much can be recording, by dumping a framebuffer stream to a portion of memory then writing to disk or encoding on the fly and uploading to cloud services, the problem here is that youre not actually giving benefit to the game environment and as a result the increased memory does not result in a "its better" outcome for game graphics.

i would be saying these exact words if it was PS4 rumored and not the Xbox One, the benefits are minimal and the downsides far outweigh the benefits.

I spent several years of my life after leaving university doing fabrication for what was then ATI, working on the Rodin core, RV516 and R600, and lastly the RV670 for FireGL shortly before leaving the company, which was later merged with AMD, so i'd like to think i know a thing or two about GPUS >_>

But alas, my point was that the rumor is BS, because it makes no sense, technically, to give it more ram, and Microsoft have gone and confirmed that it does not have the additional ram as rumored, so the discussion is over regardless.

Not sure why peopole make this statement.  You have no clue how or if 12GB will be used for the lifespan of this console. No body knows what will be the nature of games and how developers will use it in 3 years or better.  12GB just might be a way for MS to add a little future proof to the console.  Also it appears this is going to be more than just a games machine, to not go a little overboard if the money is right is a chance for a miss opportunity.

As to MS 180 in the course of the console lifespan, Who cares.  If MS is smart, they will 180 every unpopular decision they have made and bring new popular ones to the table.  It really seem silly to hate on a company overturning unpopular decisions into better ones.  Who cares if its because of competition, if competition was not in the market, then whoever is the top dog will just go for maxium profit.  We have seen it before but for some reason people seem to forget very easily when their corporation of choice is on top.