At least some NVIDIA’s ForceWare drivers cannot pass certain WHQL tests as Microsoft’s Display Compatibility Test does not pass pixel shaders 3.0 along with some other pixel shaders tests on the drivers version 66.81. Earlier this year Microsoft’s test rejected another important technology – Geometry Instancing, but on ATI’s CATALYST drivers.

OEMs Beg for WHQL

The Microsoft Display Compatibility Test kit is intended for testing display adapters and chipsets along with their drivers in order to verify their compliance with Windows XP and Windows Server 2003 operating systems and Microsoft DirectX 7, DirectX 8.1a and DirectX 9.0c specifications, which means that the test determines whether one or another hardware/software feature functions properly. Typically DCT is required to pass WHQL validation, which is important for OEMs and large system builders as well as end-users.

Technically, it is required to pass all tests, but there may be exceptions and any given vendor may run into a situation where it may not pass because of the following reasons, explained Martina Sourada, Director, Software Certification for NVIDIA Corporation:

• Test as published by Microsoft is flawed and fails, in this case, Microsoft will publish an errata which allows a vendor to submit for a logo without passing said test. Prior to making the errata public, Microsoft will issue an Incident ID which allows vendors to submit while waiting for errata to be published.
• Test may fail because vendor in question has implemented the functionality/behavior as tested by WHQL in a different manner. In this case, the vendor works with Microsoft to understand the impact of the failure. Microsoft does a very complete/thorough investigation of such failures, and if they deem that user impact is negligible, and the WHQL logo is not compromised, they will issue a Waiver.

The most recent version of the Microsoft Display Compatibility Test (DCT 5.2) puts quite a lot of attention on innovative graphics capabilities of the latest graphics processors from ATI Technologies and NVIDIA Corporation. For some reasons, at least on certain drivers and hardware the test cannot pass successfully.

Microsoft’s DCT ‘Waives’ Pixel Shaders 3.0, Geometry Instancing

Particularly, Microsoft’s DCT 5.2 fails pixel shaders 3.0 along with some other pixel shader versions tests on NVIDIA’s ForceWare 66.81 drivers along with the GeForce 6800 Ultra and the GeForce 6600 GT hardware. Earlier this year there were reports about incompatibilities of ATI’s ‘geometry instancing’ technology with Microsoft’s DCT 5.2. In order to pass the WHQL ATI had to disable the capability by default in its drivers, but to let the end-user to enable it from a special control panel. NVIDIA Corp.’s spokesperson said the company’s official public drivers would pass WHQL for sure with DCT 5.2, but did not indicate whether there are any changes with the drivers are to be made or some restrictions are to be implemented. Currently NVIDIA ships ForceWare 66.81 drivers with WHQL certification obtained under DCT 5.2 for the GeForce 6-series via its nZone web-site.

“We are currently in the process of getting a driver ready to post to the web-site that does indeed pass DCT5.2 I don’t have an exact ETA,” said Martina Sourada, Director, Software Certification for NVIDIA Corp.

“There are failures, however all failures that exist are covered by Microsoft erratas, or MS-granted waivers,” Ms Sourada added.

Pixel shaders 3.0 has been one of the main capabilities NVIDIA advertised for its latest GeForce 6 family of graphics processors. The arch-rival ATI also said recently it would follow NVIDIA with the Shader Model 3.0 feature-set in future. Even though Microsoft does not demand NVIDIA to disable pixel shaders 3.0 from the drivers, the varieties in hardware and software implementation of certain GPU capabilities definitely does not favour the convergention of hardware and software, despite of the fact that similar situation has exist for ages. NVIDIA says no problems are expected to arise on the route of the pixel shaders 3.0 adoption.

Game Developers Adopt Various Features for Different Hardware

It is unclear what exactly Microsoft’s tests dislike about certain capabilities of graphics chips, but it is evident that such approach puts certain innovations under fire and may restrict their widespread and rapid adoption by the gaming industry. Furthermore, there a question arises whether developers of graphics processors make their hardware and software products in strict accordance with the standards that they set with Microsoft Corp.

While Microsoft has allowed developers of graphics processors to roll-out a number of pixel shaders and vertex shaders versions and sub-versions, the company demands hardware makers to strictly follow the determined standards, presumably to ensure maximum compatibility between the hardware and software.

Still, at least some games and game developers even now want some more freedom and flexibility. A popular computer game FarCry recently gained support for high dynamic range rendering along with 3Dc technology. The former is implemented using standards from Industrial Light & Magic that only correspond to NVIDIA’s GeForce 6 hardware; the latter is developed by ATI Technologies and runs only on the RADEON X800/X700 hardware.