Xbox
Bill Gates unveiled the Xbox at the Game Developers Conference in 2000. At that time, Sega's Dreamcast sales were diminishing and Sony's PlayStation 2 was just going on sale in Japan.
The Xbox was the first gaming product to feature Dolby Interactive Content-Encoding Technology, which allows real-time Dolby Digital encoding in game consoles. Previous game consoles could only use Dolby Digital 5.1 during non-interactive "cut scene" playback.
The system software may have been based on the Windows NT architecture that powered Windows 2000. It exposes APIs similar to APIs found in Microsoft Windows, such as DirectX 8.1.
A derivative of the NVIDIA GeForce 3, known as the NV2A (233MHz), co-developed by Microsoft and Nvidia was used in the Microsoft Xbox game console. GeForce 3 was the first Microsoft Direct3D 8.0 compliant 3D-card. Its programmable shader architecture enabled applications to execute custom visual effects programs in Microsoft Shader language 1.1. With respect to pure pixel and texel throughput, the GeForce 3 has four pixel pipelines which each can sample two textures per clock. Features:
- Lightspeed Memory Architect (LMT) - reduce overdraw, conserve memory bandwidth by compressing the z-buffer (depth buffer) and better manage the memory bus.
- support multi-sampling and Quincunx anti-aliasing
- texture sampling units were upgraded to support 8-tap anisotropic filtering, distant textures can be noticeably sharper
NV2A: (Nvidia ceased production of the Xbox's GPU in August 2005)
- 4 pixel pipelines with 2 texture units each
- 932 megapixels/s (233 MHz × 4 pipelines)
- 1,864 megatexels/s (932 MP × 2 texture units)
- Peak triangle performance (32pixel divided from filrate)
= 932M/32 = 29,125,000 32-pixel triangles/s raw or w. 2 textures and lit.
= 970,833 triangles per frame at 30 frame/s
- Bilinear, trilinear, and anisotropic texture filtering
- 8 textures per pass, texture compression, full scene anti-aliasing (NV Quincunx, supersampling, multisampling)
- 64 MB DDR SDRAM at 200 MHz; in dual-channel 128-bit configuration giving 6400 MB/s
CPU: 32-bit 733 MHz, custom Intel Pentium III Coppermine-based processor.
- SSE floating point SIMD. Four single-precision floating point numbers per clock cycle.
- MMX integer SIMD
- 32 KB L1 cache. 128 KB on-die L2 cache
- uses uses out-of-order execution
- 133 MHz 64-bit GTL+ front-side bus to GPU
Xbox 360
The Xbox's successor, the Xbox 360, was officially unveiled announced on May 12, 2005. Xbox 360 uses the triple-core IBM designed Xenon (the cores of the processor were developed using a slightly modified version of the PlayStation 3's Cell Processor PPE architecture) as its CPU, with each core capable of simultaneously processing two threads, and can therefore operate on up to six threads at once. Graphics processing is handled by the ATI Xenos, which has 10 MB ofeDRAM. Its main memory pool is 512 MB in size.
CPU: 3.2GHz Custom IBM Central Processor, named Xenon at Microsoft and "Waternoose" at IBM.
- triple-core, two threads per core
- VMX unit per core
- 128 VMX Registers per thread
- 1MB L2 Cache (Lockable by Graphics Processor)
- uses in-order execution
- 9.6 billion dot products per second
- Unified Memory Architecture (UMA), 700MHz GDDR3 512MB RAM, 128 bit interface
- 22.40 GB/s (=700MHz*2*128/8) of memory interface bus (FSB)
Xenos: Although R500 has long since been mentioned in relation to the graphics behind Xenon, the actual development name ATI uses for Xenon's graphics is "C1". The PC graphics processor R520 and Xenos are very different.
The Xenos graphics processor consists of two distinct elements: the graphics core (shader core) and the eDRAM module. Both units running at 500MHz within the single die.
- Unified Shader Core
- 48 ALU’s for Vertex or Pixel Shader processing
- 16 Filtered & 16 Unfiltered Texture samples per clock
- 10MB eDRAM frame buffer, 32 GB/s between the eDRAM die and the GPU, 500 MB/s south-bridge
- eDRAM internal logic to its internal memory bandwidth is 256 GB/s ==> 4× FSAA, z-buffering, and alpha blending with no appreciable performance penalty on the GPU
- 48 ALU operations (one vector4 and scalar op per clock), 16 texture fetches, 32 control flow operations, and 16 programmable vertex fetch operations with tessellation per clock = 48*2 + 16 + 32 + 16 = 160 operations per cycle or 160 * 500 = 80 GOps per second
The Xbox 360 launched with 14 games in North America and 13 in Europe. The console's best-selling game for 2005, Call of Duty 2, sold over a million copies. Five other games sold over a million copies in the console's first year on the market: Ghost Recon Advanced Warfighter, The Elder Scrolls IV: Oblivion, Dead or Alive 4, Saints Row, and Gears of War.
Xbox 360 S was officially announced on June 14 2010, marketed simply as the Xbox 360, feature redesigned internal architecture with the Valhalla motherboard, which allows for around 30% more space than previous motherboards,and the XCGPU, an integrated CPU/GPU/eDRAM chip using a 45 nm fabrication process. Microsoft have said that they believe that the console is only mid-way through its life-cycle and will continue through 2015.
Xbox 360 system software (or Dashboard), is the updatable software and operating system for the Xbox 360. It resides on a 16 MB file system and has access to a maximum of 32 MB of the system's memory. Version 2.0 (11/11) supports:
- Stereoscopic 3D
- Dual play
- Updated Standard and Kinect Dashboard with Full Voice Dashboard Commandment Support
