DjLode
24-06-2004, 13:31
Da prendere con le pinze, ma girano alcuni specs su schede video custom di Ati, ovviamente queste sono riferite ad una console (xbox nuova?) ma si sa che di solito qualcosa viene trapiantato:
"Xenon Hardware Overview
By Pete Isensee, Development Lead, Xbox Advanced Technology Group
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Basic Hardware Specifications
Xenon is powered by a 3.5+ GHz IBM PowerPC processor and a 500+ MHz ATI graphics processor. Xenon has 256+ MB of unified memory. Xenon runs a custom operating system based on MS® Windows NT®, similar to the Xbox operating system. The graphics interface is a superset of MS® Direct3D® version 9.0.
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.
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GPU
The Xenon GPU is a custom 500+ MHz graphics processor from ATI. The shader core has 48 Arithmetic Logic Units (ALUs) that can execute 64 simultaneous threads on groups of 64 vertices or pixels. ALUs are automatically and dynamically assigned to either pixel or vertex processing depending on load. The ALUs can each perform one vector and one scalar operation per clock cycle, for a total of 96 shader operations per clock cycle. Texture loads can be done in parallel to ALU operations. At peak performance, the GPU can issue 48 billion shader operations per second.
The GPU has a peak pixel fill rate of 4+ gigapixels/sec (16 gigasamples/sec with 4× antialiasing). The peak vertex rate is 500+ million vertices/sec. The peak triangle rate is 500+ million triangles/sec. The interesting point about all of these values is that they’re not just theoretical—they are attainable with nontrivial shaders.
Xenon is designed for high-definition output. Included directly on the GPU die is 10+ MB of fast embedded dynamic RAM (EDRAM). A 720p frame buffer fits very nicely here. Larger frame buffers are also possible because of hardware-accelerated partitioning and predicated rendering that has little cost other than additional vertex processing. Along with the extremely fast EDRAM, the GPU also includes hardware instructions for alpha blending, z-test, and antialiasing.
The Xenon graphics architecture is a unique design that implements a superset of Direct3D version 9.0. It includes a number of important extensions, including additional compressed texture formats and a flexible tessellation engine. Xenon not only supports high-level shading language (HLSL) model 3.0 for vertex and pixel shaders but also includes advanced shader features well beyond model 3.0. For instance, shaders use 32-bit IEEE floating-point math throughout. Vertex shaders can fetch from textures, and pixel shaders can fetch from vertex streams. Xenon shaders also have the unique ability to directly access main memory, allowing techniques that have never before been possible.
As with Xbox, Xenon will support precompiled push buffers (“command buffers” in Xenon terminology), but to a much greater extent than the Xbox console does. The Xbox team is exposing and documenting the command buffer format so that games are able to harness the GPU much more effectively.
In addition to an extremely powerful GPU, Xenon also includes a very high-quality resize filter. This filter allows consumers to choose whatever output mode they desire. Xenon automatically scales the game’s output buffer to the consumer-chosen resolution.
Memory and Bandwidth
Xenon has 256+ MB of unified memory, equally accessible to both the GPU and CPU....Translated into game performance, the GPU can consume a 512×512×32-bpp texture in only 47 microseconds.
.
.
.
Eight pixels (where each pixel is color plus z = 8 bytes) can be sent to the EDRAM every GPU clock cycle, for an EDRAM write bandwidth of 32 GB/sec. Each of these pixels can be expanded through multisampling to 4 samples, for up to 32 multisampled pixel samples per clock cycle. With alpha blending, z-test, and z-write enabled, this is equivalent to having 256 GB/sec of effective bandwidth! The important thing is that frame buffer bandwidth will never slow down the Xenon GPU. "
"...this GPU does contain some of the features that the R600 will have. Like Completely Dynamic ALU assignment. and a large on Die Buffer..."
"...there are two generational lines...
R300 -> R420 -> R520
R500 (Xenon, derived from R400) -> R600 -> R...
What is R500 for the XBox falls between DX9 and DX10 - there are elements of the shader architecture that allow it to be significantly more capable than SM3.0, to DX Next like functionality but other elements that are not necessarily even SM3.0. However, XBox's R500 will be the unified shader architecture that will form the basis of ATI's DirectX Next Generation of parts but probably not R520 (which will be their SM3.0 part for the PC, based on the R300 development)."
"so basicly Xenon graphics are from the R400, R500, R600 family, and not
from the R300, R420, R520 family.... is that what you mean Dave?
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quote:
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Originally posted by DaveBaumann
More or less. My understanding at the moment on the PC front is that R520 will be their next generation SM3.0 part, but will use the R300 architectural platform as the basis. They will adopt the unified shader architecture for DirectX next in R600 and this will use what they are developing for Xenon as the basis but obviously with further developments in order to round off the DX Next specifications. Basically whatever features / functionality Xenon has will never completely come to the PC front, however the architectural platform of Xenon will be used as for DX Next (and potentially onwards) parts. I'd guess that if you used Xenon to the full you'd need a DX Next part to port it intact (graphically) across to the PC.
Development of the shader capabilities isn't really tht much of an issue, whats really being focussed on is the shader instruction scheduler - it has to get the best from a unified architecture you want as few bubbles in those ALU's as possible, so the more intelligent the scheduler is the more efficient the architecture will be."
"Xenon Hardware Overview
By Pete Isensee, Development Lead, Xbox Advanced Technology Group
.
.
.
Basic Hardware Specifications
Xenon is powered by a 3.5+ GHz IBM PowerPC processor and a 500+ MHz ATI graphics processor. Xenon has 256+ MB of unified memory. Xenon runs a custom operating system based on MS® Windows NT®, similar to the Xbox operating system. The graphics interface is a superset of MS® Direct3D® version 9.0.
.
.
.
GPU
The Xenon GPU is a custom 500+ MHz graphics processor from ATI. The shader core has 48 Arithmetic Logic Units (ALUs) that can execute 64 simultaneous threads on groups of 64 vertices or pixels. ALUs are automatically and dynamically assigned to either pixel or vertex processing depending on load. The ALUs can each perform one vector and one scalar operation per clock cycle, for a total of 96 shader operations per clock cycle. Texture loads can be done in parallel to ALU operations. At peak performance, the GPU can issue 48 billion shader operations per second.
The GPU has a peak pixel fill rate of 4+ gigapixels/sec (16 gigasamples/sec with 4× antialiasing). The peak vertex rate is 500+ million vertices/sec. The peak triangle rate is 500+ million triangles/sec. The interesting point about all of these values is that they’re not just theoretical—they are attainable with nontrivial shaders.
Xenon is designed for high-definition output. Included directly on the GPU die is 10+ MB of fast embedded dynamic RAM (EDRAM). A 720p frame buffer fits very nicely here. Larger frame buffers are also possible because of hardware-accelerated partitioning and predicated rendering that has little cost other than additional vertex processing. Along with the extremely fast EDRAM, the GPU also includes hardware instructions for alpha blending, z-test, and antialiasing.
The Xenon graphics architecture is a unique design that implements a superset of Direct3D version 9.0. It includes a number of important extensions, including additional compressed texture formats and a flexible tessellation engine. Xenon not only supports high-level shading language (HLSL) model 3.0 for vertex and pixel shaders but also includes advanced shader features well beyond model 3.0. For instance, shaders use 32-bit IEEE floating-point math throughout. Vertex shaders can fetch from textures, and pixel shaders can fetch from vertex streams. Xenon shaders also have the unique ability to directly access main memory, allowing techniques that have never before been possible.
As with Xbox, Xenon will support precompiled push buffers (“command buffers” in Xenon terminology), but to a much greater extent than the Xbox console does. The Xbox team is exposing and documenting the command buffer format so that games are able to harness the GPU much more effectively.
In addition to an extremely powerful GPU, Xenon also includes a very high-quality resize filter. This filter allows consumers to choose whatever output mode they desire. Xenon automatically scales the game’s output buffer to the consumer-chosen resolution.
Memory and Bandwidth
Xenon has 256+ MB of unified memory, equally accessible to both the GPU and CPU....Translated into game performance, the GPU can consume a 512×512×32-bpp texture in only 47 microseconds.
.
.
.
Eight pixels (where each pixel is color plus z = 8 bytes) can be sent to the EDRAM every GPU clock cycle, for an EDRAM write bandwidth of 32 GB/sec. Each of these pixels can be expanded through multisampling to 4 samples, for up to 32 multisampled pixel samples per clock cycle. With alpha blending, z-test, and z-write enabled, this is equivalent to having 256 GB/sec of effective bandwidth! The important thing is that frame buffer bandwidth will never slow down the Xenon GPU. "
"...this GPU does contain some of the features that the R600 will have. Like Completely Dynamic ALU assignment. and a large on Die Buffer..."
"...there are two generational lines...
R300 -> R420 -> R520
R500 (Xenon, derived from R400) -> R600 -> R...
What is R500 for the XBox falls between DX9 and DX10 - there are elements of the shader architecture that allow it to be significantly more capable than SM3.0, to DX Next like functionality but other elements that are not necessarily even SM3.0. However, XBox's R500 will be the unified shader architecture that will form the basis of ATI's DirectX Next Generation of parts but probably not R520 (which will be their SM3.0 part for the PC, based on the R300 development)."
"so basicly Xenon graphics are from the R400, R500, R600 family, and not
from the R300, R420, R520 family.... is that what you mean Dave?
--------------------------------------------------------------------------------
quote:
--------------------------------------------------------------------------------
Originally posted by DaveBaumann
More or less. My understanding at the moment on the PC front is that R520 will be their next generation SM3.0 part, but will use the R300 architectural platform as the basis. They will adopt the unified shader architecture for DirectX next in R600 and this will use what they are developing for Xenon as the basis but obviously with further developments in order to round off the DX Next specifications. Basically whatever features / functionality Xenon has will never completely come to the PC front, however the architectural platform of Xenon will be used as for DX Next (and potentially onwards) parts. I'd guess that if you used Xenon to the full you'd need a DX Next part to port it intact (graphically) across to the PC.
Development of the shader capabilities isn't really tht much of an issue, whats really being focussed on is the shader instruction scheduler - it has to get the best from a unified architecture you want as few bubbles in those ALU's as possible, so the more intelligent the scheduler is the more efficient the architecture will be."