Bringing it all together: The challenge in delivering a complete graphics system architecture. Chris Porthouse

Transcription

1 Bringing it all together: The challenge in delivering a complete graphics system architecture Chris Porthouse

2 System Integration & the role of standards Content Ecosystem Java Execution Environment Native Environment JSR184 3D Midlets JSR239 JSR297 2D/VG Midlet Media Midlet JSR226 JSR287 JSR135 JSR234 Java VM SVGt Native App Flash MIDI OpenKode 3D Audio Content Creation Tools OS/RTOS HAL Audio & Video Codecs TrustZone Framework ARM CPU Mali GPU Video H/W Audio Accel Standards aimed at reducing fragmentation Does compliance alone guarantee a high performance system? Where do we need standards? Where do we need innovation & differentiation?

3 System Integration Challenges System integration of hardware and software Achieve effective communication with minimal bottlenecks Integrate hardware components from different suppliers Middleware stacks from alternate suppliers The solution open standard APIs? Avoid PC graphics standards war Khronos, Java Community Process, LiMO, OMTP There are still issues to be solved Many variants/implementations of APIs? Not always working reliably Quality issues Integration issues causing performance bottlenecks in s/w

4 Legacy Graphics - SoC Configuration Push style architecture: CPU to GPU via dedicated channel Each rendering step pushed to GPU GPU dependent on CPU for vertex data CPU dependant on memory for app and scene data GPU dependent on memory for texture & frame buffer data Requires all GPU stages at full speed Even if not received data yet OS CPU App OpenGL ES DRAM TnL & Triangle setup Depth/Z Processor GPU Arbiter Rasteriser Pixel Processor Inefficient processing leads to extra power consumption = lower battery life Load balancing this architecture is difficult

5 Improved Graphics - SoC Configuration UI requires limited geometry processing All about power/performance CPU de-coupled from GPU or process the geometry on CPU Intermediate processing decoupled Main memory is source of all data While GPU rendering frame, CPU free to generate next frame Decoupling means no lock ups Power save mode recovery faster Each element in processing chain can free run, idle or shut down depending on load All structures in main memory CPU App OS OpenGL ES DRAM TnL & Triangle setup GPU Arbiter Rasteriser Depth/Z Processor Pixel Processor Benefits power savings and cost efficient performance Scaleable architecture from low geometry UI to high performance games

6 Software integration challenges High quality, high performance drivers required Fast & efficient shader compiler, efficient hardware/software interface to maximize throughput Poor quality OpenGL-ES driver can result in s/w-only performance higher than h/w accelerated! Tight integration of high quality, high performance middleware and APIs Java (JSR184, JSR297, JSR226), Flash/OpenVG 3D Applications 2D Applications M3G M3G 1.1 / (JSR-297) (JSR-184/297) Java bindings for OpenGL ES (JSR-239) JSR-226 SVGt 1.2 OpenGL ES 1.1 / 2.0 Direct3D Mobile OpenVG 1.0 GPU CPU Fabric IP Physical IP

7 Composition Efficiency in Java 2D background Render multi-source & multi-format displays Without major increase in memory & power 3D scene HI Score! 2D overlay HI Score! Java allows 2D and 3D to be combined in an image Historically all done in software A lot of GL-ES hardware not designed with Java in mind Can be worked around in software but Reduced performance, excessive copying of screen buffers

8 Composition complexity increasing Multi Layered Alpha Effects On composition Per pixel effects Composition of multiple API outputs Synchronized update of mixed media Becoming too complex to handle with software workarounds JSR287 allows video as part of 2D vector graphics JSR297 allows dynamic textures (e.g. streaming video) as part of 3D scene

9 Handling Composition Efficiency Composition efficiency being addressed in closed systems E.g. iphone, N95 browser How to integrate with 3 rd party applications? Higher level API s (OpenVG/OpenGL ES)? Overkill for most composition use cases Difficult to manipulate GPU efficiently via higher level API s Currently no mechanism for co-ordinating multiple surface updates New WG aims to provide common API for composition Simple API for windowing systems to drive composition More efficient control of composition tasks Additions to existing management API to assist

10 Summary Fragmentation - number 1 issue facing developers Standards are key to reducing fragmentation and lowering cost Hardware Differentiation CPU, GPU and bus integration to make ASIC easier to use Get power/performance ratio right for target market Software Differentiation Performance and quality of software is critical Tight integration with upper software stack (Java and native engines) Challenge is bringing this all together Removing fragmentation through standards Encouraging differentiation only if it delights consumers or reduces cost/risk Longer battery life, makes device easier to use, device visually appealing etc High quality and tight integration means faster time to market and no costly recalls Strong partnerships and understanding of whole developer community required Developers, carriers, OEMs, OS & middleware vendors, ASIC suppliers Ensure high quality, high performance integrated solutions