星期一是一个恐怖的一天，将网络浏览为NVIDIA图形卡的所有者。本周早些时候，该公司最新系列的Maxwell GPUS The GTX 900系列的新闻传动，与AMD图形卡相比，在DirectX 12中执行异步计算时，可能会损害性能。

In short: A few weeks ago, Oxide Games released a benchmark demo of an upcoming game called灰烬奇异性，the first demo for DirectX 12, the soon-to-come update to Microsoft’s popular gaming API.ManyAshesbenchmark reviews found that while NVIDIA graphics cards ran the game quite well with DirectX 11, AMD cards showed an enormous performance jump when upgrading to DX 12. NVIDIA cards, on the other hand, showed no performance improvements with DX 12, and in some cases, actually took a slight hit to performance compared to running the game with DX 11.

TheAshesbenchmark resulted in a great deal of debate and speculation online over the past few weeks. An early rumor that was quickly repeated was that NVIDIA’s current generation of GTX cards does not support asynchronous compute. AMD’s current line of graphics cards, however, do support asynchronous computing/shading.

虽然DX 11不允许异步计算/阴影，但DX 12确实如此。因此，使用DX 12的异步阴影潜力“解锁”，AMD卡可以从显着的性能提升中受益，而NVIDIA卡在尝试做同样的事情时可能会受到影响。

Reddit用户SilverforceG写道a nice overview关于R/PCGaming的争议，甚至包括一个简单的“explain it like I’m 5”summary.

从理论上讲，支持异步阴影（AMD）的GPU在处理游戏中的动态照明，阴影和全球照明时，应在DX 12中看到显着的性能增长。不支持异步阴影的GPU不会。

该消息促使许多新的900系列所有者哀叹他们的购买，在某些情况下，请联系零售商询问退款。

But is this really a death sentence for NVIDIA cards? Should you toss out your brand new GTX 980 Ti and replace it with an R9 290 from a garage sale? Maybe not quite yet.

[编辑：自从原始文章以来，这已经发生了很大变化，这要归功于下面的一些有用的评论指出了我对工具的最初误解]

A user in the Beyond3D forum created a little tool to test latency of different cards while performing graphics and compute operations. You can see results from the tool here: http://nubleh.github.io/async/scatter.html#6

Above is a graph of Fury X results. The blue line shows the amount of time taken for the pure graphics part of the work to be done. The red line shows the amount of time for the pure compute part of the work to be done. The green line shows the total time for both workloads combined. Since the green line is not a flat line consisting of red time + blue time, this indicated that asynchronous compute is working, because some of the compute work can be done at the same time as the graphics work.

The 980Ti graph, however, shows something different: The green line *is* the sum of the red and blue line. This means that for some reason the 980Ti isn’t able to do the compute work at the same time as the graphics work. It would appear that asynchronous compute isn’t working as advertised on NVIDIA cards. (The “steps” aren’t important for the question of whether asynchronous compute is working or not, the important part is whether or not green = red + blue)

What does this mean for current NVIDIA and AMD cards?

AMD graphics cards have an advantage in at least one DX 12 game, Ashes of the Singularity. They may have more advantages in other DX12 games. Completely writing off NVIDIA, however, is just silly.

NVIDIA GPU将在DX 12中继续表现良好。Ashesbenchmark is one game that utilizes asynchronous shading significantly, but we’ve yet to see any other real-world DX 12 benchmarks. We don’t know how well other upcoming games will use asynchronous shading, if they use it at all.

AMD’s Mantle/Vulkan API already use some of the features coming in DX 12, and have supported asynchronous shading for some time. While几个基准show enormous performance gains using Mantle over DX 11 (60%+ in some extreme cases), most real-world performance benefits on balanced gaming PCs are more in the 5-10% range. Very nice, but not Earth-shattering.

This controversy reminds us of a similar sky-is-falling event experienced by AMD owners a few years ago: When NVIDIA announced PhysX, gamers went nuts, and AMD owners felt like they had drawn the short stick in the GPU wars. In retrospect, of course, we know that AMD owners never really suffered too much by missing out on PhysX. And how often do you see PhysX hyped today?

We are not here to root for NVIDIA over AMD, or vice-versa. In fact, it would be nice to see AMD catch up on their lagging GPU sales, as we don’t want to see either company achieve a monopoly in the graphics card space. We just want to deal with the facts, not the hype.

从长远来看，开发人员无疑会更多地使用异步阴影。他们已经在游戏机上。但这将花费数年的时间才能以任何重要的方式进入PC游戏，因为开发人员需要学习使用新功能，并且仍希望支持旧的PC硬件。

我们的PC硬件建议will continue to be based on what works well now, and what will likely work well in the future. That includes considerations related to real-world gaming performance, acoustics, thermals, reliability and build quality. Sacrificing that viewpoint based on speculation about what may or may not happen in the future would be irresponsible.