The reason which does not adopt the Cell based graphic chip
With PS3 architecture, those where last year you are surprised graphics are to apply with Cell based architecture. Why, not making Cell based GPU?
Kutaragi: 7 SPE of Cell (Synergistic Processor Element) it can use in graphics. Actually, several of the demonstration with E3, when it has not been the graphic processor, has done everything of graphics to rendering with just Cell. But, such using is wasted. There are times when you do more in other things in Cell.
2 placing Cell, (you use Cell of one side) with also the plan which is said it was on the graphic center, but as Cell and Shader as the computer thinking that weight is different from function you stopped. We would like to make the architecture which Shader with, all things thoroughly (in graphics) can specialized Shader. Though, for example, displacing mapping (it does) with it can also say with SPE.
So far (real time 3D graphics), that it seems and shows, (3D graphics) in the space is different really. Even then, with present resolution it was good. The game which has come out with Xbox 360 the majority, is 3D such as that even at present point in time.
But, I would like to make 3D where (metamorphosis and the like is reflected securely in the 3D space). For that, there is the thought as much as possible of liking to share the data (with CPU and GPU). Therefore, the latest architecture was taken. Originally if as for the floating point unit of GPU and Cell, from precision round (making round) until error we would like to make entirely the same. This time, it has become close, almost rather simultaneous. Therefore, each other, it can use (the operational result) bidirectionally.
- EDRAM is stopped because of full HDTV
EDRAM (it installed graphic memory and DRAM) expected, but the HDTV 2 picture hearing, you could agree upon the reason which it does not make eDRAM.
Kutaragi: Originally, there is no graphic memory in GPU, Redwood (the high-speed interface which connects Cell and RSX) with YDRAM (the code name of XDR DRAM) with also correspondence is achieved. Because YDRAM (memory) has become unified.
But, so entering, that there is a problem which you say whether () definite form processing and Shader of graphics (computing) when it does, the distant place (accessing memory) with, it is possible to make (zone and cycle time) wasteful. It is not necessary to use (memory zone), with definite form task of the side of with special care Cell. Because Shader with Shader, calculates the tremendous quantity, there is a necessity of memory even to there. Especially, when with full HDTV, 2k×1k (the 1,920×1,080 dot) being progressive, when 2 pictures or more we would like to handle, it becomes, mass VRAM becomes necessary.
When that happens, eDRAM is unreasonable. As for using eDRAM, at the time of PS2 it is good. Are not enough in so or this time just 2 pictures. We assume that eDRAM of the quantity which (can support HDTV) 200 squares mm or 300 squares mm was inserted in the stone. So, when it does, (it can load onto the tip/chip logic because of the area of eDRAM) at once to decrease, the quantity of Shader decreases. That compared to, in full using in logic, the method which places large quantity Shader is better.
- NVIDIA vision of the processor of the ideal which is shared
In the first place, why uniting with NVIDIA in the GPU vendor?
Kutaragi: So far, we, Toshiba and together did the graphics for computer entertainment, personally. Including also process technology, the finish you did. And, this time, it united with NVIDIA in order to do the computer itself.
The finish pursuing PC graphics, Intel to the processor doing, it is about NVIDIA probably to do with Programable Shader. NVIDIA pursuing function and efficiency as a processor, the デビッド kirk (Chief Scientist of David B. Kirk and NVIDIA) to include the person, because the developer is graduate person of various computer enterprises such as SGI. There is a character that they, size and the like of the tip/chip do in the air, resign the fact that we would like to do and would like to pursue. Occasionally, there are also times when you do too much, but culture has been similar to me.
The approach of NVIDIA my approach, agrees in the point that finally the finish it will pursue the full programmable processor. ジェンセン (president and CEO of Jen-Hsun Huang and NVIDIA) and デビッド to be good there is an opportunity which does story, but a story that the processor of ideal it probably will do that it appears in that time. Ideal, naturally, present PC, well, is the processor which exceeds the present all processor.
They are opposite to the direction steadily, in that sense, us and vision share. It shares also the road map. In addition, they have received influence even from our architecture. Mutual temper having known, because you think, that we would like to do the same thing, it united with NVIDIA.
As for another element, display fixed pixel system (the liquid crystal and the like) the point which is moving. When it becomes fixed pixel system, TV and PC, are times when everything fuses. Therefore, we would like to support everything perfectly.
So it puts out also the downward compatibility of PS, dirty レガシー (graphics) from to up-to-date Shader would like to support entirely. As for resolution バシッ we would like to put out those above WSXGA. When such as that, rather than we making scratch (build) with, the method which the van has all is quicker (from NVIDIA).
As for Microsoft, with Xbox 360 GPU of ATI took Unified-Shader type architecture. With program characteristic Unified-Shader with advanced.
Kutaragi: As for the architecture of ATI, as for Shader however Vertex Shader and Pixel Shader equality (architecture) with, are visible at first glance well with joint ownership, you think that it is difficult. For example, whether the result of doing apex processing is made somewhere, how doing that, in Shader letting flow (for pixel processing) again? When somewhere is plugged, the stall it does entirely. Really it is different from those which are drawn in the picture. If of realistic performance is thought, you think that method of approaching NVIDIA is superior.
PLAYSTATION 3
- As for maintenance of compatibility with combination of hardware and software
As for the compatibility of past PlayStation actualizing with the hardware?
Kutaragi: You take with the combination of the hardware and the software. You try if probably to do (with just the software) how it becomes, but just which drives to perfectly close compatibility, it is important.
As for the person who develops the software unexpected, the fact that you cannot imagine is done. For example, however it is not logical as a program, you said that it moved accidentally. It is moving however, with, that is moving with, is a kind of case which is said in completely another reason. Passing through also our tests, "as for this cord/code which is what! "There are times when the cord/code which we would like to see passes.
We do not take either the compatibility for the cord/code such as that and the て is not good. ) Just a little it is painful but, because there is no logic, (to take compatibility with just the software. There are also times when hard becomes necessary. If so, this time (PS3) there is a power of extent, as for a certain place the correspondence such as with the software can do the place where it is hard.
When the cord/code of CPU side is emulated with the software, as for the endian of CPU.
Kutaragi: Therefore as for Cell bi- endian, how it becomes.
Xbox 360 takes compatibility almost with just the software. Because they have not produced the tip/chip at the respective company, it is the case that it is not the choices in other things, but how seeing?
Kutaragi: As for Xbox, when the new generation comes to November of this year, as for current Xbox you become the old generation. So when it does, Xbox means to kill by your by your. The only method of rescuing that takes 100% compatibility from first day. So or that it probably cannot commit (Microsoft), technically it is painful.
<Watch Impress Comments below>
- As for SCEI and NVIDIA those which are similar
Hisashi 夛 well, being the element, directivity of enterprise above transacting the device development and agreement of culture simply is transmitted to the relation of SCEI and NVIDIA, from word of the wooden person. Also both corporations, like original idea, with リスクテイカー, pursue to cost function and efficiency last. Is not the case, always, but the propensity such as that is strong. In addition, also both corporations, presently agree with the conception which pursues the processor.
In the GPU vendor, NVIDIA directivity to especially programmable conversion is strong. Speaking accurately, it has the direction whose also ATI Technologies and 3Dlabs are strong in programmable conversion, but it was most aggressive in NVIDIA raising general purpose. As for NVIDIA, because of that, the die/di size of GPU (the area of the semiconductor itself) it enlarges, it does not leave either the fact that production cost soars. As SCEI, that the directivity of such NVIDIA, it seems that you thought is faced as a partner.
Presently, GPU stream processing (with the small program piece keeps processing the mass data) has dashed forward to the programmable processor which specializes in stream system. By the fact that the general purpose of Programable Shader which is the operational core is raised, it is the case that it tries to be able to do, also the general-purpose processing other than graphics. It is the idea of the general-purpose processor which places the sub processor which on the one hand, also the basic idea of Cell, optimizes in stream processing. Evolving the general-purpose processor, it makes the structure which faces to the stream type processing which in the future would become important. If it tries saying, SCEI and NVIDIA are approaching to the same goal from another direction. So when you think, SCEI and NVIDIA agreed, are not strange thing with vision. You can understand also the fact that it is the agreement point which is called to the directivity both, the processor of ideal.
Hisashi 夛 well, with the graphic architecture of PLAYSTATION 3 it can support the fact that several choices were examined from explanation of the wooden person. First, with 1 Cell processor, the plan which can let do graphic processing. SPE which is the data processing processor core of Cell, SIMD (Single Instruction and Multiple Data) has the operational unit of type, can designate the same thing as Programable Shader of SIMD structure similarly basically. But, to be able to let do graphics to Cell, proper thing, it is not realistic because the efficiency of Cell as CPU is shaved.
Next, 2 loading Cell, the plan which uses Cell of one side in graphic exclusive use. Expanding the architecture for graphics Cell, it is presumed in this plan that also the plan which makes SPE for graphic processing was included. In that case, it is presumed that also loading and the like the operational unit for specification processing of graphics probably is done. Though, plan of the Cell based graphic tip/chip, is said that it went out rather at early stage.
By the way, even with present PS3 architecture, it can use Cell in graphic processing. As for Kirk of NVIDIA, with the combination of Cell and RSX, it has made clear that pre- processing and post processing of 3D graphics can be done with SPE of Cell. For example, metamorphosis is done Displacement Mapping which (displacement mapping) and the like also to do on SPE side it is possible the apex data.
SCEI eDRAM (installs in RSX and DRAM) the reason which is not placed, is clear from the picture resolution which as written even in the past, is supported. In addition, in order to actualize high Shader processing performance, thinking that it is not possible to consume the die/di area with eDRAM it is recognized. This took the special graphic architecture which utilizes the wide band of eDRAM, conception differs from Graphics Synthesizer of PS2 fundamentally. If you look at the information which is open with RSX, architecture, NVIDIA color quite is strong.
SCEI with PlayStation 2 solved the problem of compatibility by the fact that it loads the chip set of old PS as the sub processor with the hardware. Because this, unless it makes the hardware base, cannot guarantee almost 100% compatibility. When the hardware emulation is done completely with the software, enormous CPU power becomes necessary. This, like PS2 releasing the content of the hardware, in the machine which the developer that tries can access the resource freely, especially is critical.
Those where presently it is clear are basically "perfectly to have been about to actualize close" compatibility even with PS3. Because of that, as still compatibility in the hardware base the direction, continues even with PS3. However, this time, utilizing the high processing power of Cell, the interchangeability in the software base (emulator) it is taken. That specially Cell was designated as bi- endian the fact that compatibility of the CPU side is taken with Cell it means. At early stage of the cooperation development with IBM, SCEI is conveyed that it requested that bi- endian is necessary because of compatibility. By the way, this time, the compatibility of PS, PS2 and 2 generations is actualized. The both of PS and PS2 has loaded CPU of MIPS architecture.
