This post will give readers insight into the GPU device driver distribution process in the Windows PC Ecosystem. Four driver distribution channels are outlined: Inbox, IHV, OEM, and Windows Update (WU). Future posts in this series will discuss driver migration from Vista -> Windows 7, hardware support for the various WDDM driver models and DirectX version levels, and how these differences affect DirectX developers.
Every device on a Windows PC has its own driver: Network, Audio, Storage, USB, GPU, etc. Many customers don’t know what a device driver is while others update their drivers each month to get improved performance, reliability, and compatibility with the latest games and applications. We consider the entire spectrum of customers when supporting the Windows PC ecosystem. In order to coordinate Microsoft’s support strategy for these customers with our OEM and IHV partners, the Windows PC Ecosystem has four driver distribution channels which we’ll discuss below.
Microsoft provides GPU drivers on the Windows 7 retail DVD on behalf of our top GPU IHV partners (AMD/ATI, Intel, and Nvidia). These drivers provide baseline functionality for about 75% of the GPU marketplace so that customers can have an easy out-of-box setup experience. These drivers are designed and written by the IHV, but are integrated into Microsoft’s development and test engineering processes to ensure compatibility. In addition, the integration of these drivers into the Windows build actually accelerates the OS development process itself because it allows us to identify and resolve issues more efficiently. Some technologies such as OpenGL, CrossFire, SLI, and Hybrid/switchable graphics are absent from the Inbox driver. (For more information on why certain technologies lack Inbox support, please see the Windows 7 Graphics Guide.)
GPU devices that do not have Inbox drivers are covered by WU which we’ll discuss later. If no inbox or WU driver is available, Windows will load the Standard VGA driver provided by Microsoft which implements the VESA standards. For most systems, this driver will deliver the common display resolutions on a single monitor, the Windows Basic theme without Aero, and limited power management support so the display is still usable. Below is a summary of GPU support available on the Windows 7 retail DVD.
Inbox Driver Version (INF)
Radeon 9500 -> Radeon HD 4870
GMA 950 -> GMA X4500
GeForce 6xxx -> 9xxx,
(*Notebook support provided by Verde program)
The Inbox drivers provide a good baseline, but IHV’s continue to innovate and improve their products through new hardware releases and driver updates. IHV drivers may be downloaded directly from vendor websites such as www.amd.com, www.intel.com, www.nvidia.com, or loaded from a disc included in a retail package. Compared to Inbox drivers, IHV-supplied drivers are updated on a regular basis and tend to have more bug fixes, performance tweaks, and extra features such as OpenGL, CrossFire, SLI, and advanced control panel applets. Windows PC enthusiasts and hardcore gamers download the latest IHV drivers to get the best performance and compatibility with games and graphics intensive applications. For example, ATI, Intel, and Nvidia all list compatibility bug fixes and performance improvements in their latest driver release notes. Most driver updates are not necessary for most customers. But for major reliability fixes which eliminate blue screen errors or TDR hangs, IHV’s can post their drivers on WU as optional downloads and can request they be offered to customers as important updates, when applicable. This delivery mechanism allows the driver to get into the hands of many more customers as we’ll explain later.
OEMs such as HP and Dell typically include customized GPU drivers on their systems which are tested exclusively with the particular hardware platform. These drivers are pre-loaded on the hard drive of shipping systems but can also be downloaded from OEM support websites. Laptop drivers typically have dozens of customizations specific to the hardware feature set and a driver INF file which associates the driver package with the exact PNPID of the hardware device.
The PNPID-level customization allows more control over driver distribution. For example, if a customized OEM driver is installed, WU will not offer end-users a generic or IHV-supplied WU driver unless it is specifically targeted for the user's system by the OEM. This scheme gives OEMs more end-to-end control over their products and streamlines product support by reducing the variability in the driver versions that can be installed. This reduced variability helps the OEM maintain a reliable and consistent experience for their customers. But there is a tradeoff: IHV’s continue to innovate with regular driver updates, but many OEM customers are not able to get those updates since the OEM won’t necessarily post them right away.
WU drivers provide baseline support for GPU devices which do not have Inbox drivers. If a customer is using the default Standard VGA driver after OS install or after installing a new video card, the WU client will automatically check the WU servers to see if a better driver is available for download. Depending on which WU options have been previously set on the machine, the driver may download and install automatically, or the customer may be prompted to accept the download. As new devices are released to market, IHVs and OEMs will continue to post drivers on their own support web sites and WU.
WU also provides a mechanism to widely distribute fixes for customer issues with previously installed drivers. End-users may not know about IHV or OEM websites or may not have the technical expertise or confidence to manually install drivers. So Microsoft works closely with OEM and IHV partners to address known issues and deliver updates automatically via WU. When a partner has a new driver update ready, they can post the driver as an optional download on WU. After several days of customer downloads, Microsoft analyzes reliability trends using opt-in customer feedback tools such as Windows Error Reporting. In fact, the use of these tools enables Microsoft to track reliability on all drivers regardless of the distribution channel. The data is analyzed and aggregated so noteworthy trends can be shared with IHV and OEM partners allowing them to target fixes more effectively. Based on this deep analysis, Microsoft may promote optional driver downloads to important downloads so that more customers get the fixes automatically.
We hope this post sheds some light on the driver distribution process for the Windows PC Ecosystem. Stay tuned for follow-up posts describing driver migration from Vista -> Windows 7, hardware support for the various WDDM driver models and the DirectX version levels. In the meantime you can look at the cardcaps.pdf document included in the latest DirectX SDK for a breakout of DirectX capabilities vs. GPU device.