DirectX 10.1 levels playing field between Nvidia and AMD

Posted at: 12:30pm 3rd August 2007 by Ben Hardwidge

Shader Model 4.1’s multi-sampling anti-aliasing patterns will make benchmark comparisons more ‘meaningful,’ says AMD

Microsoft has released a BETA SDK for its forthcoming API revision, DirectX 10.1, which includes Shader Model 4.1, and AMD claims this will help to make fairer benchmark comparisons between Nvidia and ATi cards.

Among Shader Model 4.1’s features is ‘The ability to select the MSAA sample pattern for a resource from a palette of patterns, and retrieve the corresponding sample positions,’ which has made AMD very excited indeed. Richard Huddy, head of AMD’s European Developer Relations team, told Custom PC that ‘the fact that 2x, 4x and 8x multi-sample anti-aliasing (MSAA) all have to be supported (and with exactly the same sampling patterns)’ would be a ‘big gain for consumers.’ Huddy claimed that this would ‘allow “exact” comparisons of images rendered with MSAA enabled, so that direct benchmark comparisons will now always be meaningful.’

Huddy said that the new API ‘eliminates one of the minor but annoying differences between different vendor's hardware,’ but also described the changed in some of Shader Model 4.1’s other graphical features. ‘The two most obvious changes to affect games programmers will be in the enhancement of the Vertex Shader,’ saids Huddy, ‘which is now allowed to export up to 32 elements instead of the previous maximum of just 16.’ Huddy said that this ‘will generally reduce the number of passes that hardware takes to render complex surfaces.’

As well as this, games that used deferred rendering, such as Ghost Recon: Advanced Warfighter, will be helped along by the ability to have individual blend modes per target when using multiple render targets. Huddy said that ‘AMD welcomes all of these changes and will be enthusiastic in its support of DirectX 10.1.’ He then cryptically added: ‘Expect timely announcements from us...’

As well as the addition of Shader Model 4.1, DirectX 10.1 also adds a replacement for DirectSound called XAudio2, which we’re currently investigating.