Vertex and Geometry Processing Selection Capability for Microsoft DirectX* 10 White Paper For Intel G45 Express Chipsets and Mobile Intel GM45 Express Chipsets November 2009 Document Number: 322931-001
INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS OTHERWISE AGREED IN WRITING BY INTEL, THE INTEL PRODUCTS ARE NOT DESIGNED NOR INTENDED FOR ANY APPLICATION IN WHICH THE FAILURE OF THE INTEL PRODUCT COULD CREATE A SITUATION WHERE PERSONAL INJURY OR DEATH MAY OCCUR. Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. The information here is subject to change without notice. Do not finalize a design with this information. The products described in this document may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request. Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order. All products, platforms, dates, and figures specified are preliminary based on current expectations, and are subject to change without notice. All dates specified are target dates, are provided for planning purposes only and are subject to change. This document contains information on products in the design phase of development. Do not finalize a design with this information. Revised information will be published when the product is available. Verify with your local sales office that you have the latest datasheet before finalizing a design. Intel and the Intel logo are trademarks of Intel Corporation in the U.S. and other countries. *Other names and brands may be claimed as the property of others. Copyright 2009, Intel Corporation. All rights reserved. 2 White Paper
Contents 1 Introduction...5 1.1 Terminology...5 1.2 Reference Documents...5 2 Vertex and Geometry Processing Selection Capability...6 2.1 Introduction...6 2.2 Integrated Graphics Architecture...6 2.3 Why Vertex and Geometry Processing Selection Capability?...7 2.4 Driver Architecture...7 2.5 Benefits of Vertex and Geometry Processing on Processor and Graphics Engines...9 2.6 Summary...11 Figures Figure 1. 3D and Media Kernels...6 Figure 2. Vertex and Geometry Processing Architecture...8 Figure 3. Vertex and Geometry Processing Options in CUI...9 Figure 4. Intel G45 Express Chipset Performance - Using Processor Accelerated Vertex and Geometry Processing with DirectX 10- based Applications...10 Figure 5. Intel G45 Express Chipset Performance Benefits - Using Graphics- Accelerated Vertex and Geometry Processing with DirectX 10-based Applications10 White Paper 3
Revision History Revision Number Description Revision Date -001 Initial release. November 2009 4 White Paper
Introduction 1 Introduction The purpose of this document is to explain what the vertex and geometry processing selection capability is, and what the benefits are. The document is targeted for OEMs, system integrators, and end-users that will be building or using motherboards with Intel G45 Express Chipsets; and Mobile Intel GM45 Express Chipsets. 1.1 Terminology Term Description TnL PSGP SWVP HWVP VGPSC Transform and lighting Processor-Specific Geometry Pipeline: Code path that performs Vertex processing calculation on the processor inside the D3D runtime. Software Vertex Processing: Vertex Processing that takes place on the CPU utilizing the PSGP Hardware Vertex Processing: Vertex Processing that (traditionally) takes place on a graphics chip only Vertex and Geometry Processing Selection Capability 1.2 Reference Documents Document Vertex Processing Selection Capability White Paper Document No./Location http://www.intel.com/design/chipsets /g965/documentation.htm#papers White Paper 5
2 Vertex and Geometry Processing Selection Capability 2.1 Introduction Intel has released the 15.16 version driver for Microsoft Windows Vista* operating systems that includes support for Microsoft Windows* 7 operating systems. With the release of this driver, Intel further extends the capabilities of vertex processing for Microsoft DirectX* 10. With this technology, Intel is able to deliver a better gaming experience by adding additional platform performance in order to deliver higher frame rates and increased game compatibility. 2.2 Integrated Graphics Architecture The Intel GMA HD architecture is based on a unified shader architecture that is comprised of a collection of highly-programmable, and scalable, 32-bit floating point engines. This programmable architecture is one based upon a unified shader model which means both vertex, geometry, and pixels shaders run on the same programmable engines or execution units. These same programmable engines are also able to process media codecs, as well as various filters for text and image processing. The Intel graphics driver architecture delivers scalability and flexibility by supporting features within kernels that are compiled for the Intel graphics architecture. At the highest level, there are kernels that support 3D and media. Within 3D there are kernels for DirectX and SGI OpenGL*. DirectX then has kernels that support pixel and vertex shading, and filtering. OpenGL has fragment and vertex shading, as well as filtering kernels. The media kernels are codec dependent, but capabilities like IDCT (Inverse Discrete Cosine Transform), motion compensation, and filtering techniques like advanced de-interlacing would all be supported by a kernel. Figure 1. 3D and Media Kernels. Figure 1. 3D and Media Kernels 6 White Paper
2.3 Why Vertex and Geometry Processing Selection Capability? In the process of designing and enabling a driver that supports Vertex Processing and TnL, Intel engineers discovered that some applications, mainly 3D games, performed better with vertex and geometry processing done on the processor rather than on the graphics engine. As mentioned above, the architecture uses the same programmable engines to process all shaders. By off-loading some of the vertex and geometry shader processing to the processor, the graphics engine is able to process more pixel shader data and do additional work like anisotropic filtering. Therefore, the graphics engine is able to do more while staying within market required power, thermal, and cost envelopes. Separate vertex shader, geometry shader, and pixel shader units within the graphics engine were a potential design option for Intel graphics engines. However, upon analysis of various 3D applications, it was discovered that the vertex and geometry traffic is at the beginning of each scene, and only accounted for about one-third of the computing requirements for a scene. On the other hand, pixel traffic is about twothirds of the scene and required most of the computing resources. So for much of the time the vertex shaders would be sitting idle. 2.4 Driver Architecture In previous versions of DirectX, there was a path that allowed the processor to do vertex processing called the PSGP. Applications had to take this path into account and support a path for vertex processing on the processor and graphics cores. Intel Engineers have developed a more optimized CPU vertex and geometry processing module and integrated it into the graphics driver, thus integrating the capabilities of the PSGP into the driver. When an application calls the D3D runtime environment (which then calls the graphics driver for vertex or geometry processing), the driver makes a decision to either have the processor or graphics engine process the workload. The processing of the data on either the processor or graphics engine returns the same result to the application. That is, Intel did not induce error or somehow change the data in a way that achieved additional performance beyond using a different engine to process the data. However, Intel did optimize the memory management of being able to swap data between the processor and graphics engines. Determination as to which applications either process on the processor or graphics engine is based upon a list contained within the graphics inf that can be edited by Intel s customers. The list is based upon stringent application performance validation results. This technology has a huge benefit to the platform, as the best performance path can be used for 3D applications. Figure 2 shows the new path that utilizes VGPSC. Intel also made this capability selectable by the end-user. Under the CUI (Common User Interface) there is a tab for 3D. The user clicks the box labeled custom settings. Under the heading of Vertex Processing there are three options: Default, Application Settings, and Enable Software Processing. The default is Enable Software Processing. The CUI also has a help capability. The user can click the help button (? symbol) and then hover over a feature for a brief explanation of the feature, as shown White Paper 7
in Figure 3. If the Enable Software Processing option is enabled, then either the graphics engine or CPU is used depending on the application. If Application Settings is enabled, then the graphics engine is used for all vertex and geometry processing. Figure 2. Vertex and Geometry Processing Architecture VGPSC 8 White Paper
Figure 3. Vertex and Geometry Processing Options in CUI 2.5 Benefits of Vertex and Geometry Processing on Processor and Graphics Engines The main motivation for this capability was to increase application performance on all Intel 4 Series Express Chipsets. Intel had previously used this technology with DirectX 9 to increase the performance on Intel 3 Series and Intel 965 Series Express Chipsets. Figure 4 shows some games that benefit from having the processor compute the vertex and geometry data on Intel G45 Express Chipset with DirectX 10. The data shows that when the processor is used relative to using the graphics engine for vertex and geometry processing some applications perform better with the processor. Conversely, Figure 5 shows some applications that perform better using the graphics engine for vertex and geometry processing with DirectX 10. White Paper 9
Figure 4. Intel G45 Express Chipset Performance - Using Processor Accelerated Vertex and Geometry Processing with DirectX 10- based Applications Figure 5. Intel G45 Express Chipset Performance Benefits - Using Graphics- Accelerated Vertex and Geometry Processing with DirectX 10-based Applications 10 White Paper
2.6 Summary Intel has released graphic driver version 15.16 for Windows Vista operating systems with support for Windows 7 operating systems that extends the capabilities of the Vertex and Geometry Processing Selection Capability (VGPSC) for Intel Series 4 Express Chipsets. Results show that some 3D applications perform best with using the processor for vertex and geometry processing for DirectX 10. In other instances, results show that some 3D applications perform best with using the graphics engine on Intel G45 Express Chipset for DirectX 10. The Intel driver has been developed to provide the optimum performance path for 3D applications. Intel s goal is to provide the best user experience possible for 3D applications. White Paper 11