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VGLeaks: Durango's Move Engines
- Thread starter ekim
- Start date
Gemüsepizza
Member
I'm sure the GPU can access both of them at the same time, but the illustration makes it look like the GPU can read 8224MB (8192+32) at 170GB/s, when in reality it can only read 8192MB at 68GB/s and 32MB at 102GB/s.
especially if there is another GPU in the box (which developers would have no clue of, so you wouldn't see a vgleaks article on it)
it's a way to merge the output from the OS from another GPU while adding functionality to developers
but the most important part of Durango consistently seems to be Quality of Service.
MS appears to be attempting to reduce and remove almost every potential detraction from the hardware done by the OS
Angelus Errare
Banned
Not really if you read both at the same time its 102GB/s + 68GB/s. His point was you can't add the bandwidth together. If DDR3's bandwidth is 68GB/s that's as fast as you'll ever be able to write to that pool. Likewise if eSRAM's maximum bandwidth is 102GB/s that's all you'll ever be able to write at. Even if you can write to both of them cocurrently it'll still always be 102GB/s + 68GB/s. Never 170GB/s.
It's like saying 360 has 280GB/s of memory bandwidth. Or PS3 has 48GB/s of bandwidth.
Hehe, it never ceases to amaze me that people are really bothered by that bandwidth figure.
Gemüsepizza
Member
But why add them together when looking at read speed and not when looking at write speed? The GPU can read both memory pools at the same time but not write to them at the same time? And why are they using 102GB/s for write speed, when they can only write with 68GB/s to DDR3 and 102GB/s to ESRAM? Those additions seem kind of arbitrary.
Yeah, all of that makes sense (and tons of other uses), but you can easily do that in software.
Gemüsepizza;47581479 said:
I do think that 102GB/s is strange -- perhaps when they post the article this will be answered. edit: If it can only write to one pool at a time this would make sense, since the maximum write speed in the diagram would be the greater of the two (102)
Isn't it just to support DVR and system menus etc? Game just uses one and the OS can overlay PiP or a menu without the game having to care.
Angelus Errare
Banned
Werll it should bother people because I foresee 2 years into the generation people will still be going "720 has 170GB/s of bandwidth."
Better now to squash misconceptions than let them run amok.
hint: there's possibly another GPU in durango, which would make this kinda necessary
and also "easily" does not mean there'd be no negative performance impact in doing it... when trying to increase performance
McHuj
Member
Gemüsepizza;47581479 said:
Yes, it's very possible that it can read from both at once but only write to one at a time. Reading from a memory is a lot easier than writing to one.
It should probably have probably have an either/or path for the write 102 or 68 GB/sec. The other possibility is that the GPU can only write to SRAM, but I believe it's already been said that it can render to DDR3 so that's probably not it.
MaulerX
Member
Exactly. Reading both simultaneously does indeed give it 170GB/s (read). If this info is a year old (without Microsoft knowing about Orbis specs) then it's not like they purposefully added that figure to make it seem on par with Orbis. Writing speeds are different. But then again, the diagram explains all that and it seems technically accurate.
AgentP
Thinks mods influence posters politics. Promoted to QAnon Editor.
Gemüsepizza;47580706 said:
It seems the GPU sees a virtualized memory pool. This is a theoretical max, both pools (eSRAM and DDR) would have to be doing nothing else (no writing, no Northbridge r/w, etc.) other than being read by the GPU and of course the GPU is reading two separate chunks of data (unless there is just a copy in both).
MaulerX
Member
From I can discern the GPU can read both at the same time but not write at the same time. I assume the reason they used the 102GB/s figure for the write speed is because that is the theoretical max it can write (to esRAM).
phosphor112
Banned
Pretty straight forward diagram. Where'd it come from?
http://kotaku.com/5982986/we-know-all-about-the-next-xbox-from-someone-who-says-theyve-got-one
Nm, i see a new thread for it.
Nm, i see a new thread for it.
http://www.vgleaks.com/durango-display-planes/
VGLeaks posted this link but nothings showing up for me
VGLeaks posted this link but nothings showing up for me
THE:MILKMAN
Member
Insane Metal
Member
Today we present another Durango GPU custom feature shown in our first exclusive article: the display planes.
The Durango GPU supports three independent display planes, which are conceptually similar to three separate front buffers. The display planes have an implied order. The bottom plane is combined with the middle plane using the middle plane’s alpha channel as an interpolation factor. The result of this operation is combined with the top plane using the top plane’s alpha channel as an interpolation factor. Blending occurs at 10-bit fixed-point precision. The following diagram illustrates the sequence of operations.
The three display planes are independent in the following ways, among others:
They can have different resolutions.
They can have different precisions (bits per channel) and formats (float or fixed).
They can have different color spaces (RGB or YCbCr, linear or sRGB).
Each display plane can consist of up to four image rectangles, covering different parts of the screen. The use of multiple screen rectangles can reduce memory and bandwidth consumption when a layer contains blank or occluded areas.
The display hardware contains three different instances of various image processing components, one per display plane, including:
A hardware scaler.
A color space converter.
A border cropper.
A data type converter.
Using these components, the GPU converts all three display planes to a common output profile before combining them.
The bottom and middle display planes are reserved for the running title. A typical use of these two planes is to render the game world at a fixed title-specified resolution, while rendering the UI at the native resolution of the connected display, as communicated over HDMI. In this way, the title keeps the benefits of high-quality hardware rescaling, without losing the pixel-accuracy and sharpness of the interface. The GPU does not require that all three display planes be updated at the same frequency. For instance, the title might decide to render the world at 60 Hz and the UI at 30 Hz, or vice-versa. The hardware also does not require the display planes to be the same size from one frame to the next.
The system reserves the top display plane for itself, which effectively decouples system rendering from title rendering. This decoupling removes certain output constraints that exist on the Xbox 360. For example, on Durango the system can update at a steady frame rate even when the title does not. The system can also render at a lower or higher resolution than the title, or with different color settings.
There it is
Lord Error
Insane For Sony
What he was saying was cagey/confusing. IIRC, he never said what specs were wrong, or that PS4 was or wasn't more powerful. He said something along the lines that some very old leaked specs were outdated, and that compared to those, PS4 appeared better than it would compared to latest specs, but never said which. He's only really been vocal in saying that always online / no used games rumor was wrong.
should make a new thread
Lot's of "ads" posts imcoming... :-/
Insane Metal
Member
I don't think it's necessary, there's nothing really interesting there. But if anyone feel like doing it...
THE:MILKMAN
Member
Playing Watchdogs you walk past a car dealership and a ad pops up for a special deal tailored to you for a Durango. Only $39,999.99.
Something like that?
Insane Metal
Member
That should be really nice for the Dashboard.
wont stop anyone
McHuj
Member
Or for DLC, "buy now to unlock content this content"
Or a persistent semi-translucent ad in a corner (ala TNT/TBS TV programming)
having hardware that can do it though is gonna be faster than rendering to a target in software.
Actually if you're merging "planes" with GPU during a resolve/present you could do a few of these completely free (bandwith permitting).Durante said:
It's set-top box/non-game ambitions. PS2 supported 2 planes because GPU was designed for use in set-top boxes - and it's obvious THAT machine was not doing it to save on pixel-cycles.
And as I said before, the main advantage of merging in scanout is being able to completely decouple refresh of different planes - it allows for nice walling-off of resources. No need for synchronizing eg. OS and game plane updates mean you don't end up with the usual XMB/Dashboard/Steam overlay slowdowns we've all gotten used to.