Now that NVidia finally has DX11 hardware available, Microsoft has the chance to compare how well the ATI RadeonHD cards stand up to the new GTX480/470.  Specifically, they were looking for oddities in the DirectX11 implementation, and found one particularly interesting one in NVidia’s use of the “Feature Level” concept.

The ATI Radeon HD 5000 Series only provides one quality level per sample count, while the NVIDIA GeForce GTX 470/480 exposes a number of fine-grain quality levels per sample count. This highlighted a few UI bugs in some of the samples as well as DXUT/DXUT11 that were corrected in the June 2010 release. Be sure to test the behavior of any MSAA settings and quality levels in your DX10.x and DX11 programs on both vendor's hardware.

The guys at Geeks3d took both cards for a spin to get the actual results from the ‘CheckMultisampleQualityLevels’ Microsoft mentions, and sees the obvious difference.

Here are the details for a GTX 480 (with R257.15 drivers – Win7 64-bit):

Direct3D 10 - Adapter 0 - Description: NVIDIA GeForce GTX 480
Direct3D 10 - Adapter 0 - Dedicated video memory: 1503MB
Direct3D 10 - Adapter 0 - vendorId: 10DE, deviceId: 06C0, revision: 00A3
Direct3D 10 - MSAA 2X supported with 3 quality levels
Direct3D 10 - MSAA 4X supported with 17 quality levels
Direct3D 10 - MSAA 8X supported with 33 quality levels

And here are the details for a HD 5870 (with Catalyst 10.5 – Win7 64-bit):

Direct3D 10 - Adapter 0 - Description: ATI Radeon HD 5800 Series
Direct3D 10 - Adapter 0 - Dedicated video memory: 1014MB
Direct3D 10 - Adapter 0 - vendorId: 1002, deviceId: 6898, revision: 0000
Direct3D 10 - MSAA 2X supported with 1 quality levels
Direct3D 10 - MSAA 4X supported with 1 quality levels
Direct3D 10 - MSAA 8X supported with 1 quality levels

via DirectX 11 Hardware Vendor Differences – Games for Windows and the DirectX SDK – Site Home – MSDN Blogs.

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