Back in August, there was some potentially shocking news for those who follow the graphics card industry. A benchmark using an upcoming real-time-strategy game called Ashes of the Singularity showed that DirectX 12, the newest graphics API for Windows, heavily favored graphics cards from Advanced Micro Devices (AMD -4.11%). I wrote back in July that DirectX 12 wasn't likely to benefit AMD relative to rival NVIDIA (NVDA -4.40%), but these benchmarks seem to fly in the face the of that argument.
That benchmark, done by Ars Technica , shows that AMD's R9 290X, a graphics card launched in 2013, performed considerably better under DirectX 12 compared with DirectX 11. NVIDIA's highest-end card did worse under DirectX 12, and it was very nearly eclipsed by the 290X. Amazingly, a $300-$350 GPU from AMD is producing almost the same performance as NVIDIA's $650 flagship in this benchmark.
The explanation for this surprising result is a DirectX 12 feature called asynchronous compute. In a nutshell, async compute allows a graphics card to process multiple streams of commands simultaneously, allowing the graphics hardware to be more fully utilized. This feature needs to be implemented in hardware, and AMD's GCN graphics architecture has supported it since 2011. Based on the initial comments from the developer behind Ashes, NVIDIA's Maxwell graphics cards performed worse when async compute was enabled, which suggests that the architecture doesn't support the feature.
This rumor that NVIDIA doesn't support async compute was eventually debunked. The second-generation Maxwell architecture, which includes all of NVIDIA's 900 series cards, does support async compute, but it wasn't fully implemented in the drivers at the time of the benchmark. AMD and NVIDIA implement the feature in different ways, but both companies support it.
A second DirectX 12 benchmark was released in September, this time using Fable Legends, an upcoming game built on the popular Unreal Engine 4. Anandtech ran the benchmark, and the results are more in line with what one would expect. In this case, NVIDIA's GTX 980 Ti easily wins out, beating AMD's high-end Fury X as well as the 290X. According to Anandtech, the benchmark does use async compute, although it may not be used as heavily compared to the Ashes benchmark.
What it all means
One thing to remember is that all of these benchmarks are based on games that haven't been released yet, on a graphics API that is brand new, and on graphics drivers that are very early. These results should all be taken with a grain of salt.
I'm sticking with the conclusion from my previous article: DirectX 12 is unlikely to disproportionately benefit either AMD or NVIDIA. Because AMD's GCN and NVIDIA's Maxwell have their differences, it's certainly possible for a developer to design a game that works better on one or the other. But with NVIDIA currently claiming a discrete graphics card market share in excess of 80%, it's hard to imagine that a developer would go this route.
DirectX 12 is not a silver bullet for AMD. The company has fallen badly behind NVIDIA, with its market share being cut in half over the past year, and its latest batch of new graphics cards have done little to change the story. As AMD struggles with big losses in its PC business, NVIDIA's GPU business is thriving despite a currently weak PC market. DirectX 12 will certainly be good for PC gamers, but it's unlikely to give AMD an advantage.