HiGame

Nvidia has released the Game Ready 334.75 WHQL graphics driver, with optimized support for World of Warcraft’s latest Warlords of Draenor expansion, Far Cry 4, Dragon Age Inquisition, and The Crew. Alongside those new titles comes support for a new capability that Nvidia touted when it launched the Maxwell family: MFAA, or Multi-Frame Anti-Aliasing.

What is MFAA?

The term antialiasing refers to a wide range of rendering techniques designed to reduce the appearance of jagged, crawling lines on a moving render surface. There are multiple techniques to reduce the appearance of these visual artifacts, from rendering the scene internally at 2-4x the current resolution (supersampling), to sampling line edges and geometry but avoiding the need to sample textures multiple times (multisampling), to performing edge detection and smoothing in software without the need for sub-pixel sampling (Fast Approximate Antialiasing, or FXAA).

Each of these technologies comes with a performance tradeoff, and both AMD and Nvidia have experimented with implementing various types of filters, temporal antialiasing, and in Nvidia’s case, TXAA. MFAA is different from TXAA, in that TXAA requires the game developer to specifically implement the rendering method in each title and uses sample information from previous frames to create smoother output. It was explicitly designed to give game developers the ability to implement a more cinematic feeling to a title and is designed to improve on MSAA’s rendering without the performance hit of supersampling.



MFAA is similar to TXAA in that it also uses temporal sampling in its algorithm, but it doesn’t implement the same pixel-shader filters or require the same degree of engine integration. Nvidia is still working to add support for more games, but MFAA is currently available in 20 titles, including Assassin’s Creed Unity, Battlefield 4, Civilization 5, Civilization: Beyond Earth, Crysis 3, and Titanfall. We’ll be examining the just-released Assassin’s Creed Unity to see if MFAA can alleviate some of the frame rate problems we saw in that title with antialiasing enabled.

The goal of MFAA is to offer equivalent antialiasing at higher frame rates. So 4xMFAA would, ideally, take a 2x MSAA performance hit but offer 4xMSAA quality, if not a little higher.

One other feature we want to mention is that Maxwell’s MFAA supports a much larger set of sampling patterns than any previous Nvidia GPU. Some of you may recall that 5-6 years ago, it was possible to force GeForce cards of a certain vintage to use ordered-grid supersampling (OGSSAA) in certain titles. This type of supersampling carried an enormous performance hit and blurred the final image, but it could nearly eradicate jagged lines. Normally, GPUs have a pre-programmed series of sampling methods baked into ROM and there’s nothing the end-user can do to change them — if the GPU performs OGSSAA with a square pattern, that’s what you get.



Maxwell-class hardware (currently the GTX 980, GTX 970, and GTX 980M) store patterns in RAM and can vary them from frame to frame depending on on-screen activity. The result of this should be better antialiasing overall, at every quality level.


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