NVIDIA claims partially support DirectX 11.1
Since the launch of Nvidia GPUs based on Kepler graphics architecture was reported that these bear only directx 11, information that can be corroborated in Nvidia’s own website, but strangely for several months in the control panel drivers Nvidia for Windows 7 provides API supported directx 11.1 as, even though we know that Windows 7 does not support DirectX 11.1 . So Are Nvidia kepler GPUs support DirectX 11.1?
From the strict point of view, to refer to a GPU as support some version of the DirectX API, this has required express support (hardware) to it, and from this point of view we have Nvidia Kepler GPUs (GTX 600 Series) do not support API DirectX 11.1 (but if the DirectX 11 API). But what with the info in the Nvidia control panel?
Nvidia claims that its GPUs are partially compatible with DirectX API 11.1, and that is if they are not physically compatible with DirectX 11.1, software can emulate some of the features of the API (using the CPU, with the obvious decrease in performance) , obviously there are DirectX 11.1 API functions that would be very expensive (in terms of yield loss) emulated by software, which simply states that their Nvidia GPUs do not support them, among which are:
- Target-Independent Rasterization (2D rendering only).
- 16xMSAA Rasterization (2D rendering only).
- Orthogonal Line Rendering Mode.
- UAV (Unordered Access View) in non-pixel-shader stages.
Nvidia claims that these instructions will not be used in future games, but functions as if it will be used in the games if their GPUs will be supported in the feature using hardware Feature Level 11 (via software) DirecX 11.1; between these functions are:
- partial buffer constant updates.
- Logic operations in the Output Merger.
- 16bpp rendering.
- UAV-only rendering (only 8 of the 64 slots Compatible DirectX 11.1).
- Partial clears.
- Large constant buffers.
Nvidia says not only withstand the unique features of the API DirectX 11.1 (Hardware Level DirectX 11.1), but if the other functions, a situation that they themselves recognize as confusing, but in reality there is nothing confusing, because traditionally the new versions of Microsoft DirectX API to allow use by software from some of its functions in hardware designed for older versions of DirectX (thanks to those already named DirectX Hardware Levels ). As clarified that this is a feature of Microsoft’s API, which is not confined to Nvidia Kepler GPUs, but all market DirectX 11 GPUs (GeForce 400, 500, Radeon HD 5000 and 6000 Series).
At this point I should mention that it is not the first time we have a situation like this in the world of GPUs, where a manufacturer takes advantage of this feature of DirectX (Hardware Level) to advertise their product as compatible with a version of DirectX supported above the physically; example of this is in the (at the time) controversial GPUs Nvidia GeForce 4 MX Series, which claimed to be compatible with DirectX 8.1 ( page 2 of the PDF of Nvidia ), when in fact only bear DirectX 7 by hardware.
Some game developers claim that the differences between DirectX 11 and DirectX 11.1 are minimal, and that 90% of them can be covered by software (emulated), so as to games would not be a determining factor not having the express support DirectX 11.1.
Meanwhile AMD claims withstand 100% hardware functions DirectX 11.1 (Level Hardware DirectX 11.1) in their architecture based GPUs Graphics Graphics Core Next “BCM” (used in GPUs Radeon HD 7750 and higher). So, to end this confusing issue we need only GCN based AMD GPUs are 100% compatible with DirectX 11.1, while DirectX 11 GPUs based on different architectures to GCN are “partially compatible with DirectX 11.1″.
Link: Nvidia Does not Fully Support DirectX 11.1 GPU with Kepler, But … (Bright Side of News)Tags: API, directx, directx 11.1, emulation, games, geforce, hardware, Hardware Level, kepler, Microsoft, Nvidia, partial, software, support