Xenos
Encyclopedia
The Xenos is a custom graphics processing unit (GPU) designed by AMD
(former ATI
), used in the Xbox 360
video game console
. Developed under the codename "C1," it is in many ways related to the R520
architecture and therefore very similar to an ATI Radeon X1900/X1950 series of PC graphics cards as far as features and performance are concerned. However, the Xenos introduced new design ideas that were later adopted in the R600
series, such as the unified shader architecture. The package contains two separate silicon dies, the GPU and an eDRAM
, featuring a total of 337 million transistors.
groups with 16 processors per group, for a total of 48 processors. Each of these processors is composed of a 5-wide vector unit (total 5 FP32 ALUs) that can serially execute up to two instructions per cycle (a multiply and an addition). Thus each of the 48 processors can perform 10 floating-point ops per cycle. All processor in a SIMD group execute the same instruction, so in total up to three instruction threads can be simultaneously under execution.
Advanced Micro Devices
Advanced Micro Devices, Inc. or AMD is an American multinational semiconductor company based in Sunnyvale, California, that develops computer processors and related technologies for commercial and consumer markets...
(former ATI
ATI Technologies
ATI Technologies Inc. was a semiconductor technology corporation based in Markham, Ontario, Canada, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technologies Inc., the company was listed publicly in 1993 and was acquired by Advanced Micro...
), used in the Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...
video game console
Video game console
A video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...
. Developed under the codename "C1," it is in many ways related to the R520
Radeon R520
ATI's "R520" core is the foundation for a line of DirectX 9.0c and OpenGL 2.0 3D accelerator X1000 video cards. It is ATI's first major architectural overhaul since the "R300" core and is highly optimized for Shader Model 3.0. The Radeon X1000 series using the core was introduced on October 5,...
architecture and therefore very similar to an ATI Radeon X1900/X1950 series of PC graphics cards as far as features and performance are concerned. However, the Xenos introduced new design ideas that were later adopted in the R600
Radeon R600
The graphics processing unit codenamed the Radeon R600 is the foundation of the Radeon HD 2000/3000 series and the FireGL 2007 series video cards developed by ATI Technologies...
series, such as the unified shader architecture. The package contains two separate silicon dies, the GPU and an eDRAM
EDRAM
eDRAM stands for "embedded DRAM", a capacitor-based dynamic random access memory integrated on the same die as an ASIC or processor. The cost-per-bit is higher than for stand-alone DRAM chips but in many applications the performance advantages of placing the eDRAM on the same chip as the processor...
, featuring a total of 337 million transistors.
Specifications
On the chip, the shader units are organized in three SIMDSIMD
Single instruction, multiple data , is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data simultaneously...
groups with 16 processors per group, for a total of 48 processors. Each of these processors is composed of a 5-wide vector unit (total 5 FP32 ALUs) that can serially execute up to two instructions per cycle (a multiply and an addition). Thus each of the 48 processors can perform 10 floating-point ops per cycle. All processor in a SIMD group execute the same instruction, so in total up to three instruction threads can be simultaneously under execution.
- 500 MHz 10 MiBMIBMIB may refer to any of several concepts:* Master of International Business, a postgraduate business degree* Melayu Islam Beraja, the adopted national philosophy of Brunei* Motion induced blindness, a visual illusion in peripheral vision...
daughter embedded DRAMEDRAMeDRAM stands for "embedded DRAM", a capacitor-based dynamic random access memory integrated on the same die as an ASIC or processor. The cost-per-bit is higher than for stand-alone DRAM chips but in many applications the performance advantages of placing the eDRAM on the same chip as the processor...
(@256GB/s) framebufferFramebufferA framebuffer is a video output device that drives a video display from a memory buffer containing a complete frame of data.The information in the memory buffer typically consists of color values for every pixel on the screen...
on 90 nm process.- NEC designed eDRAM die includes additional logic (192 parallel pixel processors) for color, alpha compositingAlpha compositingIn computer graphics, alpha compositing is the process of combining an image with a background to create the appearance of partial or full transparency. It is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a...
, ZZ-bufferingIn computer graphics, z-buffering is the management of image depth coordinates in three-dimensional graphics, usually done in hardware, sometimes in software. It is one solution to the visibility problem, which is the problem of deciding which elements of a rendered scene are visible, and which...
/stencilStencil bufferA stencil buffer is an extra buffer, in addition to the color buffer and depth buffer found on modern computer graphics hardware. The buffer is per pixel, and works on integer values, usually with a depth of one byte per pixel...
buffering, and anti-aliasingAnti-aliasingIn digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution...
called “Intelligent Memory”, giving developers 4-sample anti-aliasingAnti-aliasingIn digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution...
at very little performance cost. - 105 million transistors
- 8 Render Output unitRender Output unitThe Render Output Unit, often abbreviated as "ROP", and sometimes called Raster Operations Pipeline, is one of the final steps in the rendering process of modern 3D accelerator boards. The pixel pipelines take pixel and texel information and process it, via specific matrix and vector operations,...
s- Maximum pixelPixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
fillrate: 16 gigasamples per second fillrate using 4X multisample anti aliasing (MSAA), or 32 gigasamples using Z-only operation; 4 gigapixels per second without MSAA (8 ROPs × 500 MHz) - Maximum Z sample rate: 8 gigasamples per second (2 Z samples × 8 ROPs × 500 MHz), 32 gigasamples per second using 4X anti aliasing (2 Z samples × 8 ROPs × 4X AA × 500 MHz)
- Maximum anti-aliasing sample rate: 16 gigasamples per second (4 AA samples × 8 ROPs × 500 MHz)
- Maximum pixel
- NEC designed eDRAM die includes additional logic (192 parallel pixel processors) for color, alpha compositing
- 500 MHz parent GPU on 90 nm90 nanometerThe 90 nm process refers to the level of CMOS process technology that was reached in the 2002–2003 timeframe, by most leading semiconductor companies, like Intel, AMD, Infineon, Texas Instruments, IBM, and TSMC....
, 65 nm65 nanometerThe 65 nm process is an advanced lithographic node used in volume CMOS semiconductor fabrication. Printed linewidths can reach as low as 25 nm on a nominally 65 nm process, while the pitch between two lines may be greater than 130 nm.. For comparison, cellular ribosomes are...
or 45nm45 nanometerPer the International Technology Roadmap for Semiconductors, the 45 nm technology node should refer to the average half-pitch of a memory cell manufactured at around the 2007–2008 time frame....
TSMCTSMCTaiwan Semiconductor Manufacturing Company, Limited or TSMC is the world's largest dedicated independent semiconductor foundry, with its headquarters and main operations located in the Hsinchu Science Park in Hsinchu, Taiwan.-Overview:...
process of total 232 million transistors- 48 floating-pointFloating pointIn computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
vector processors for shaderShaderIn the field of computer graphics, a shader is a computer program that is used primarily to calculate rendering effects on graphics hardware with a high degree of flexibility...
execution, divided in three dynamically scheduled SIMD groups of 16 processors each.- Unified shading architectureUnified shader modelUnified Shader Model term is used to describe two similar but separate concepts: Unified Shading Architecture and Unified Shader Model.- Unified Shader Model :...
(each pipeline is capable of running either pixel or vertex shaders) - 10 FP ops per vector processor per cycle (5 fused multiply-add)
- Maximum vertexVertex (geometry)In geometry, a vertex is a special kind of point that describes the corners or intersections of geometric shapes.-Of an angle:...
count: 6 billion vertices per second ( (48 shader vector processors × 2 ops per cycle × 500 MHz) / 8 vector ops per vertex) for simple transformed and lit polygons - Maximum polygonPolygon (computer graphics)Polygons are used in computer graphics to compose images that are three-dimensional in appearance. Usually triangular, polygons arise when an object's surface is modeled, vertices are selected, and the object is rendered in a wire frame model. This is quicker to display than a shaded model; thus...
count: 500 million triangles per second - Maximum shader operations: 96 Billion shader operations per second (3 shader pipelines*16 processors*4 ALUs*500 MHz)
- 240GFLOPS
- MEMEXPORT shader function
- Unified shading architecture
- 16 texture filtering units (TF) and 16 texture addressing unit (TA)
- 16 filtered samples per clock
- Maximum texelTexel (graphics)A texel, or texture element is the fundamental unit of texture space, used in computer graphics. Textures are represented by arrays of texels, just as pictures are represented by arrays of pixels....
fillrate: 8 gigatexel per second (16 textures × 500 MHz)
- Maximum texel
- 16 unfiltered texture samples per clock
- 16 filtered samples per clock
- Maximum Dot productDot productIn mathematics, the dot product or scalar product is an algebraic operation that takes two equal-length sequences of numbers and returns a single number obtained by multiplying corresponding entries and then summing those products...
operations: 24 billion per second - Support for a superset of DirectXDirectXMicrosoft DirectX is a collection of application programming interfaces for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with Direct, such as Direct3D, DirectDraw, DirectMusic, DirectPlay,...
9.0c API DirectX Xbox 360, and Shader Model 3.0+
- 48 floating-point
- CoolingComputer coolingComputer cooling is required to remove the waste heat produced by computer components, to keep components within their safe operating temperature limits.Various cooling methods help to improve processor performance or reduce the noise of cooling fans....
: Both the GPU and CPU of the console have heatsinksHeat sinkA heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid. Examples of heat sinks are the heat exchangers used in refrigeration and air conditioning systems and the radiator in a car...
. The CPU's heatsink uses heatpipeHeat pipeA heat pipe or heat pin is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces....
technology, to conduct heat from the CPU to the fins of the heatsink. The heatsinks are actively cooled by a pair of 60 mm exhaust fans. The new XCGPU chipset redesign is featured in the Xbox 360 S and integrates the CPU (XenonXenon (processor)Xenon is a CPU that is used in the Xbox 360 game console. The processor, internally codenamed "Waternoose", which was named after Henry J. Waternoose III in Monsters Inc. by IBM and XCPU by Microsoft, is based on IBM's PowerPC instruction set architecture, consisting of three independent processor...
) and GPU (XenosXenosThe Xenos is a custom graphics processing unit designed by AMD , used in the Xbox 360 video game console. Developed under the codename "C1," it is in many ways related to the R520 architecture and therefore very similar to an ATI Radeon X1900/X1950 series of PC graphics cards as far as features...
) in one chip and is actively cooled by a single heatsink rather than two.