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The Myths Of Graphics Card Performance: Debunked, Part 2

Vendor-Specific Technologies: Mantle, ShadowPlay, TXAA And G-Sync

Let us start by making a clear statement: we applaud both AMD and Nvidia for their groundbreaking work in pushing the envelope of what is possible on PC gaming platforms.

Low-Level APIs: AMD's Mantle

Mantle is designed to give developers more direct control of hardware, following in the distant footsteps of Glide. Some of you may be too young to understand why that comparison is important, but it is.

Glide was introduced by 3dfx to complement and closely mirror the graphics capability of its Voodoo Graphics card. OpenGL was a massive beast for 1990s hardware, and Glide contained a smaller subset of features that were easy to learn and implement. The API’s main downside was its specificity to 3dfx hardware, just as Mantle is currently specific to AMD hardware.

Eventually, DirectX and full OpenGL drivers matured, and a variety of additional hardware appeared (does anyone remember the Riva TNT?). These developments led to the dusk of Glide as a mainstream API.

Mantle is an interesting gamble by AMD. With already-established ecosystems relying on OpenGL and DirectX, the need for a new low-level API is debatable, although AMD claims that developers are clamoring for it).

Currently, Mantle support is limited to a handful of titles. The SDK is in beta, and currently limited to a handful of developers selected by AMD. And, as our own tests in AMD Mantle: A Graphics API Tested In Depth show, Mantle’s primary benefit is reducing CPU overhead, limiting its most noticeable benefit to low-end CPUs coupled with high-end GPUs.

I believe that Mantle's success will ultimately hinge on two factors:

  1. Whether Mantle is easy enough to code that DirectX/OpenGL ports aren't too cumbersome for developers
  2. Whether Mantle’s performance gains extend to enthusiast-class platforms

We took our time in covering Mantle with real performance data. But the story linked above is illuminating if you haven’t already read it.

Advanced Temporal Antialiasing: Nvidia's TXAA

I often use the example of humanity putting a man on the moon before figuring out that it was a good idea to put wheels on suitcases as an example of how sometimes brilliantly simple ideas go overlooked for a very long time with no good reason. MLAA and FXAA, Class B post-processing-based anti-aliasing techniques are one such innovation.

A further take on anti-aliasing, available only from Nvidia and then only on a few game titles, goes a step further. It builds on the fact that some of the most annoying aliasing artifacts, referred to as "shimmering", happen because of movement across frames. By analyzing not a single frame, but rather a sequence of them, it is possible to predict where those artifacts will appear and compensate accordingly.

Nvidia's TXAA is a variation of MSAA. The company says that "TXAA uses a contribution of samples, both inside and outside of the pixel, in conjunction with samples from prior frames". Hence you can expect its image quality to exceed even Class A anti-aliasing algorithms at the cost of even more memory and throughput (FPS).

Should they mature enough, temporal-based multi-sampling anti-aliasing technologies could be defined by us as a new "Class A+". We'd also love to see an implementation of MLAA/FXAA that leverages, in addition to the current frame, the prior frame in its post-processing calculation. We bet such additional information could be put to good use for improving image quality.

G-Sync And FreeSync: No More The Compromise Between V-sync On And Off

We covered Nvidia's G-Sync technology extensively in the already-mentioned G-Sync Technology Preview: Quite Literally A Game Changer, and we'd point you in that direction for a deep-dive if you want to learn more.

We also mentioned FreeSync, which was added to the DisplayPort 1.2a standard as the Adaptive-Sync amendment. AMD recently announced that it’s collaborating with MStar, Novatek and Realtek to enable scalers able to drive the next generation of FreeSync-capable monitors. According to the company, its newest graphics cards already support dynamic frame rates in games, and the rest of the ecosystem should begin materializing in 2015.

Kudos to Nvidia for leading the way in innovation on this front, and to AMD for proposing a free, open standard for the benefit of gamers at every budget point.

Other Vendor-Specific Technologies Worth Mentioning

Below is a list of vendor-specific technologies that are applicable to specific cases, such as running more than one monitor or card, stereoscopic gaming, gameplay recording and so on. We’ll let you explore them through each vendor’s website.

GPU-Based Physics Calculations

Multi-Display Technologies

Gameplay Recording Technologies

Cooperative Rendering Technologies

Stereoscopic Gaming Technologies

Computing Libraries Support

Multi-Card Rendering Technologies