Question about the PS3's non unified RAM ...

I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.Question about the PS3's non unified RAM ...
[QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE] You're getting it backwards. The video RAM is what the PS3 is short on. 256MB of main memory is enough for what the PS3 does. Also, the video memory is GDDR3, not XDR. The MAIN MEMORY is XDR.Question about the PS3's non unified RAM ...
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[QUOTE=''mjarantilla''][QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE] You're getting it backwards. The video RAM is what the PS3 is short on. 256MB of main memory is enough for what the PS3 does. Also, the video memory is GDDR3, not XDR. The MAIN MEMORY is XDR.[/QUOTE]Oh...lol. Than why cant developers dip into the XDR? Is it blocked of or something?
Sonys latest dev kits allow developers to easily combine the ram. At least that is the last I have heard.
[QUOTE=''Wasdie'']Sonys latest dev kits allow developers to easily combine the ram. At least that is the last I have heard.[/QUOTE]Shame most games would have taken a long time to develop and probably are too late in development to take advantage of this shocking development.
[QUOTE=''Wasdie'']Sonys latest dev kits allow developers to easily combine the ram. At least that is the last I have heard.[/QUOTE] Really? Linky Please.
[QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE]

1. It doesn't limit the PS3. The RSX is a Turbocache GPU, it can access and utilize both VRAM and system RAM. A game system is going to use more RAM for graphics/video than anything else. So it is a case where the GPU would need to supplement with system RAM rather than vice versa.

2. Specialization. VRAM is great for loading and unloading large amounts of data at ounce but isn't as practical for smaller discrete data transactions.
[QUOTE=''skektek''][QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE] 1. It doesn't limit the PS3. The RSX is a Turbocache GPU, it can access and utilize both VRAM and system RAM. A game system is going to use more RAM for graphics/video than anything else. So it is a case where the GPU would need to supplement with system RAM rather than vice versa. 2. Specialization. VRAM is great for loading and unloading large amounts of data at ounce but isn't as practical for smaller discrete data transactions.[/QUOTE]So dev problems are arising from cell...not the memory architecture.
[QUOTE=''the_dark-knight''][QUOTE=''Wasdie'']Sonys latest dev kits allow developers to easily combine the ram. At least that is the last I have heard.[/QUOTE] Really? Linky Please.[/QUOTE]See that is the thing I have only heard about it. I don't really have a link. So it could be false. Yet seeing games like Uncharted, Killzone 2, GT5 P, I don't think the ram is a problem.
[QUOTE=''the_dark-knight''][QUOTE=''skektek''][QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE] 1. It doesn't limit the PS3. The RSX is a Turbocache GPU, it can access and utilize both VRAM and system RAM. A game system is going to use more RAM for graphics/video than anything else. So it is a case where the GPU would need to supplement with system RAM rather than vice versa. 2. Specialization. VRAM is great for loading and unloading large amounts of data at ounce but isn't as practical for smaller discrete data transactions.[/QUOTE]So dev problems are arising from cell...not the memory architecture.[/QUOTE]What development problems are you speaking of?
[QUOTE=''skektek''][QUOTE=''the_dark-knight''][QUOTE=''skektek''][QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE] 1. It doesn't limit the PS3. The RSX is a Turbocache GPU, it can access and utilize both VRAM and system RAM. A game system is going to use more RAM for graphics/video than anything else. So it is a case where the GPU would need to supplement with system RAM rather than vice versa. 2. Specialization. VRAM is great for loading and unloading large amounts of data at ounce but isn't as practical for smaller discrete data transactions.[/QUOTE]So dev problems are arising from cell...not the memory architecture.[/QUOTE]What development problems are you speaking of?[/QUOTE]Well I believe GTAIV was pushed back do to optimizing the PS3(imo) so what was their difficulties with the PS3?
Yes mainly from cell. Programming for a regular CPU is a normal process, with the use of sub processors that take the load off the man CPU. With Cell, it is made up of LOTS of sub processors all of which are independantly programable, and that causes for super complex code and program layouts for full function of the cell processor. Where as regualr CPU's jsut have multithreading, its taken to a new level with the Cell and some developers jsut don't care to spend the huge amount of extra time and money to learn it jsut for one console. It's too bad they havent tried to invade the PC market more with cell, because they COULD make it a standard if they tried hard enough. obviously bluray was their main focus.
[QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE]It is limiting because too many developers refuse to learn new hardware, and instead, just want to make every game as if it is for PC. With PCs, developers have massive amounts of RAM they essentially use as a crutch. They don't have to worry about efficiency or what type of hardware the user actually has, because that isn't their problem. They just dump as much infor into RAM as they can.When it comes to consoles, the RAM is much less for a number of reasons. However, the PS3 is designed to be a streaming machine and not a ram-dump. So, for developers to make games properly for the system, they have to take it apart, spread the data across the spu's (or whatever they are called) and the recompile the data at the end. It should all be done streaming. When developers use the hardware properly, you get games like Uncharted. However, most devs can't be bothered (maybe budget, maybe time, etc) and so they just try and squeeze their RAM-dump game onto the PS3 with minimal optimization.
In SW, PS3 has RAM issues. In the real world, UT3, Uncharted, GT5P and other games proves the contrary.
[QUOTE=''ZIMdoom''][QUOTE=''the_dark-knight'']I know it has 256mb of ram and 256mb of ram dedicated the the video card. My questions is 1. How does this limit the PS3? If you have 256mb of ram...why cant devs just dip into the video memory? Is that video memory just going to waste? Also...how is it limiting the PS3 2. how is this beneicial at all for the PS3? Why would sony dedicate the 256mb oof ram for the PS3 video? Iknow that the video memory is XDR...making it waaaaaay faster than just ddr or something.[/QUOTE]It is limiting because too many developers refuse to learn new hardware, and instead, just want to make every game as if it is for PC. With PCs, developers have massive amounts of RAM they essentially use as a crutch. They don't have to worry about efficiency or what type of hardware the user actually has, because that isn't their problem. They just dump as much infor into RAM as they can.When it comes to consoles, the RAM is much less for a number of reasons. However, the PS3 is designed to be a streaming machine and not a ram-dump. So, for developers to make games properly for the system, they have to take it apart, spread the data across the spu's (or whatever they are called) and the recompile the data at the end. It should all be done streaming. When developers use the hardware properly, you get games like Uncharted. However, most devs can't be bothered (maybe budget, maybe time, etc) and so they just try and squeeze their RAM-dump game onto the PS3 with minimal optimization. [/QUOTE]Could you imagine how sexy GTAIV could have looked if it were PS3 exclusive? If they utilized everything about ps3? You guys think it would look similar to what it is now? AAnd shouldn't euphoria be better on PS3 since it is a physics heeavy system...which the cell excells in.
I've posted this at least a hundred times.http://research.scea.com/ps3_deferred_shading.pdfGuess what it's about?The pixel shader runs on the Synergistic Processing Elements
(SPEs) of the Cell/B.E. and works concurrently with the GPU to
render images. The system's unified memory architecture allows
the Cell/B.E. and GPU to exchange data through shared textures.
The SPEs use the Cell/B.E. DMA list capability to gather
irregular fine-grained fragments of texture data generated by the
GPU. They return resultant shadow textures the same way. The
shading computation ran at up to 85 Hz at HDTV 720p
resolution on 5 SPEs and generated 30.72 gigaops of
performance. This is comparable to the performance of the
algorithm running on a state of the art high end GPU. These
results indicate that the Cell/B.E. can effectively enhance the
throughput of a GPU in this hybrid system by alleviating the
pixel shading bottleneck. I.E. textures can be shared through shared memory in the Playstation 3 to use integrated, concurrent rendering. This is something the XBox 360 can absolutely NOT do. The Xbox 360 has ''shared'' memory, not ''unified'' memory. You have 512 megs, and then the developer partitions. Unless anybody can give some kind of developer commentary proving that statement false rather than true.The Xbox 360 ends up with partitioned memory....the PS3's memory is naturally partitioned, but the partitions can be overridden, thus removing any fanboy-imposed performance roadblock.By the way, this is straight from Sony, and they've actually done this already. Meaning the memory is unified, period. Thank you.
Good question. I guess it all depends on how the developers use the hardware. For instance, there is an IBM tech demo using a cell processor (similar to the PS3 spu) that can perform realtime raytracing (with additional elements,GI, ambient, specular...etc) without the GPU. So maybe some limitations in GPU memory can be overcome by utalizing the SPUs for certain tasks.
[QUOTE=''BobHipJames'']I've posted this at least a hundred times.http://research.scea.com/ps3_deferred_shading.pdfGuess what it's about?The pixel shader runs on the Synergistic Processing Elements
(SPEs) of the Cell/B.E. and works concurrently with the GPU to
render images. The system's unified memory architecture allows
the Cell/B.E. and GPU to exchange data through shared textures.
The SPEs use the Cell/B.E. DMA list capability to gather
irregular fine-grained fragments of texture data generated by the
GPU. They return resultant shadow textures the same way. The
shading computation ran at up to 85 Hz at HDTV 720p
resolution on 5 SPEs and generated 30.72 gigaops of
performance. This is comparable to the performance of the
algorithm running on a state of the art high end GPU. These
results indicate that the Cell/B.E. can effectively enhance the
throughput of a GPU in this hybrid system by alleviating the
pixel shading bottleneck. I.E. textures can be shared through shared memory in the Playstation 3 to use integrated, concurrent rendering. This is something the XBox 360 can absolutely NOT do. The Xbox 360 has ''shared'' memory, not ''unified'' memory. You have 512 megs, and then the developer partitions. Unless anybody can give some kind of developer commentary proving that statement false rather than true.The Xbox 360 ends up with partitioned memory....the PS3's memory is naturally partitioned, but the partitions can be overridden, thus removing any fanboy-imposed performance roadblock.By the way, this is straight from Sony, and they've actually done this already. Meaning the memory is unified, period. Thank you.[/QUOTE]Nice find James.
[QUOTE=''Phazevariance'']Yes mainly from cell. Programming for a regular CPU is a normal process, with the use of sub processors that take the load off the man CPU. With Cell, it is made up of LOTS of sub processors all of which are independantly programable, and that causes for super complex code and program layouts for full function of the cell processor. Where as regualr CPU's jsut have multithreading, its taken to a new level with the Cell and some developers jsut don't care to spend the huge amount of extra time and money to learn it jsut for one console. It's too bad they havent tried to invade the PC market more with cell, because they COULD make it a standard if they tried hard enough. obviously bluray was their main focus.[/QUOTE]

Multi threading on the Cell is essentially the same as multi threading on any other (multi execution unit) processor it is just a question of degree. The PS3 has nine threads of execution while developers are still wrapping their heads around trying to use 2 - 4 threads. IBM's Octopiler helps* but it takes time for tools and experience to mature.



*if developers want to get the absolute most out of the Cell they would still need build their engines from the ground up specifically for the Cell.