I believe so. I think there's a default mode, and then the devs can encourage certain behaviour for the tiling system. We know for sure they can provide their own scheduling for example. No idea where this idea of mine can be confirmed though!
Will tiling in 360 allow reaching 60 fps performance ?
- Thread starter Love_In_Rio
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scooby_dooby
Legend
!eVo!-X Ant UK said:
I believe this is the importance of a predicated tiling engine.
When an engine is built from the ground up to use predicated tiling, it's geometry hits are much less, and tiling into 3 tiles is supposed to be <5% performance hit, and ATI has even claimed you actually gain performance in some cases by implemnting predicated tiling.
If you have to tack tiling into an engine after the fact, I've heard it said that it's more like a 10-20% performance hit for tiling 3/4 tiles.
To our knowledge, there no engines being used right now that were built from the ground up to use predicated tiling, so it will take a long time before we see what the 360 is really capable of.
This is where Sony made a good choice with the RSX, it's initial titles should be easier for dev's to extract power from with their existing game engines, whereas Xenos requires some redesign, so the initial titles are not so impressive...couple that with the very late dev-kits and it's no wonder many launch titles are sub-par.
Shifty Geezer said:
Hm... Maybe Dave can confirm? I was just re-reading the Xenos article last night, and I don't think it explicitly states that the tiling can be modified. I might just be having a memory issue, but my original question probably came from a vague memory of reading that devs could change the tiling behaviour.
Thanks though.
RavenFox said:
Prowess is not the point of this thread. He gave an example of a game using AA at 720p, which is also 60fps. i.e. tiling does not hinder getting 60fps performance for this game and there lies the critical idea that Platon already said: it's up to the developer.
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I don't understand though why XB360 launch games lack predicated tiling, as emulation was supported from early kits IIRC. There's a predicated tiling library in the SDK and I thought it was there from early on. I guess if games started development on PC systems and the dev kits with tiling emulation turned up too late, that might account for it. I've been unable to confirm this info from a Google. Maybe someone else knows where and when the first news of the tiling library appeared?scooby_dooby said:
As I've said (to you I believe) before, the limitations on Xenos rendering abilities due to lack of tiling are confined to the niceties like free AA and loads of alpha effects (read particles). The amount of geometry and texture and shader power available isn't limited over what's available due to a lack of tiling. It's more likely launch games aren't pushing the envelope due to the usual time constraints etc. than an absence of predicated tiling.
Alstrong said:Prowess is not the point of this thread. He gave an example of a game using AA at 720p, which is also 60fps. i.e. tiling does not hinder getting 60fps performance for this game and there lies the critical idea that Platon already said: it's up to the developer.
Trust me I understand that but what is the game really tasking that gives it that benefit? An open world? Mutiple characters on screen with complex AI? Hey why not multiple vehicles on screen with all that plus complex physics and great track detail. Your point is well taken but Ill stick to my original post of that game is not a good benchmark of 360 muscle.
A side question:
Isn't Xenos's eDram supposed to be able to accelerate stencil shadows?
While is also be able to smooth their edges or as I guess the parent die's shaders will have to do that still? (which could limit it's value)
Is there a good possiblity it'll be shadowmaps for the PS3 and stencil shadows for the X360...or not even the X360 devs will still continue to use stencils?
Isn't Xenos's eDram supposed to be able to accelerate stencil shadows?
While is also be able to smooth their edges or as I guess the parent die's shaders will have to do that still? (which could limit it's value)
Is there a good possiblity it'll be shadowmaps for the PS3 and stencil shadows for the X360...or not even the X360 devs will still continue to use stencils?
scificube said:
Since the 6xxx series, nvidia chips have had double Z-rate (no-colour). I don't see any good reason why they would change that for RSX. Xenos and RV530 are actually the only two designs with double Z-rate from ATi. So in the end, both offerings for consoles should be good to go with stencil shadows.
Not too sure how well Xenos deals shadow buffers. nVidia does have PCF and DST to help... hm...
Of course, the usage of either will also depend on the look that the developers are going with for the game. Stencil shadows seem to give off a very moody feel with the hard edges and general darkness with dynamic lighting. And it doesn't necessarily have to be dark; just look at the Halo 2 announcement trailer and the E3 2003 demo. IMO, there was quite a different feel to the look when they switched to shadowmaps.
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Could someone of the devs/techheads around here say how long time and how much work it is to rewrite an engine to allow predicated tilling from the ground up and how long it would take to make an engine capable for tilling after the fact? Must the whole engine be rewritten if you want predicated tilling?...
Those are purely down to art&design choices though - on PS2 you have games using stencil shadows give you just about any number of different looks (including cartoony ones). And vast majority of them are using soft-edged shadows as well (from what I've seen I'd say PS2 stuff used hard-edge volume shadows only in the early years).
Or you could look at MGS4 demo which borrowed volume shadowing model from SH games, and still comes off with a visual feel very close to the rest of MGS series
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scooby_dooby
Legend
Platon said:
scooby_dooby
Legend
Are the 360 developers under NDA with regard to tiling on Xenos? It sure seems like it... *walks away whistling *
inefficient
Veteran
scooby_dooby said:
It's simply that no one wants to let the competition know what they are doing.
A little bit of open knowledge sharing bettween studios would ultimately benifit everyone. But corporate execs usually don't go for that sort of thing.
Vysez, what I said was an opinion (imo), not a claim of truth.
Zbuffer for pixel depth calculation is on edram, so no tapping on main memory. AA-sampling and light calculation on pixels (hdr, ocllusion) are done on edram-core logic, so no tapping on main memory. Tiles are rendered sequentially (tile1, tile2, tile 3):
So, tile1 is rendered on shaders, put in post-process on edram-core logic, and then send to main memory. Tile1 is just part of the whole image, so smaller data size goes thru the gpu-mem pipeline, therefore more BW for everything else (bigger data flow for 360cpu). I know 5% penalty, but we don`t know what native framerate is at fully optimised conditions in x360 (which you can not achieve without tiling, catch22); blocked cpu can drag fast gpu down.
Anyway, I could never give negative points to others for speaking out their (even erroneus) thoughts, so I am in disbelieve that someone gave me bad reputation on something so trivial as this.
Lysander said:
Zbuffer for pixel depth calculation is on edram, so no tapping on main memory. AA-sampling and light calculation on pixels (hdr, ocllusion) are done on edram-core logic, so no tapping on main memory. Tiles are rendered sequentially (tile1, tile2, tile 3):
So, tile1 is rendered on shaders, put in post-process on edram-core logic, and then send to main memory. Tile1 is just part of the whole image, so smaller data size goes thru the gpu-mem pipeline, therefore more BW for everything else (bigger data flow for 360cpu). I know 5% penalty, but we don`t know what native framerate is at fully optimised conditions in x360 (which you can not achieve without tiling, catch22); blocked cpu can drag fast gpu down.
Anyway, I could never give negative points to others for speaking out their (even erroneus) thoughts, so I am in disbelieve that someone gave me bad reputation on something so trivial as this.
ihamoitc2005
Veteran
Edram
I do not think edram tiling will make frame-rate low or high. 30fps has 2x CPU and GPU clock cycles (clockspeed/fps) for creation of one frame no? So frame-rate is developer choice for shader and CPU use.
Edram tiling method is for AA no? So choice is HD with AA (tiling) or if no tiling then HD with no AA, or low resolution with AA.
Without tiling graphics can be better if low resolution with AA is developer choice. This is because low resolution required screen has less pixels so more shader cycles per pixel is possible for more shader effects on pixels. Maybe this is why some developers say 1080P for PS3 is not so great idea also maybe 480P Revolution will have same or almost same look as PS3 or Xbox360 games on normal TV.
Love_In_Rio said:
I do not think edram tiling will make frame-rate low or high. 30fps has 2x CPU and GPU clock cycles (clockspeed/fps) for creation of one frame no? So frame-rate is developer choice for shader and CPU use.
Edram tiling method is for AA no? So choice is HD with AA (tiling) or if no tiling then HD with no AA, or low resolution with AA.
Without tiling graphics can be better if low resolution with AA is developer choice. This is because low resolution required screen has less pixels so more shader cycles per pixel is possible for more shader effects on pixels. Maybe this is why some developers say 1080P for PS3 is not so great idea also maybe 480P Revolution will have same or almost same look as PS3 or Xbox360 games on normal TV.
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