For something that won’t be seeing the light of day until next year, DirectX 12 is in the news an awful lot. Whether it be on the PC or the Xbox One, a week doesn’t go by without the new API popping up on the radar. And for good reason, its release will certainly resolve a lot of the problems associated with PC development, and because its DX11 compatibility it’ll maintain the air of familiarity for developers who don’t require DX12 optimization.
The CEO of StarDock, Brad Wardell recently took to twitter to speak out on the subject of DX12. A user started out by tweeting Wardell “Spencer said DX12 won’t be a massive change. You think he meant development or performance?”
Wardell responded. development is basically the same. My general impression is that Mantle is higher perf but DX12 is slightly “safer”. It’s less API and more implementation. I wish the people arguing this topic were more technical. It’s pretty simple.”
I then Tweeted him, “I think Phil was asking people to be realistic with expectations, a performance boost but not 588%. That’s how I read his tweets”.
Wardell then responded to my Tweet by saying, “hard to tell. Mantle gave our engine a 6x boost over dx11 on same hardware. and before someone takes that out of context 6x was showing lots of units at once. Ymmv.”
Right there Wardell has hit home several key points in a few statements. Firstly, it’s likely Mantle will be the better performing API. To those who’re familiar with the tech industry, this news is hardly revolutionary. AMD’s API is tailored made for a specific architecture (AMD’s own GCN based cards) and thus can be ‘thinner’ still than DX12. DX12 isn’t vendor specific, and compatibility with AMD, Nvidia and Intel (among others) is crucial.
Since DX12 was announced to the public, lots of assumptions and claims have been made regarding its performance. While Phil Spencer’s message has made a lot of waves around the industry, the message is pretty simple – the DirectX already inside the X1 is low level (to a degree). The performance boost likely won’t be as high as desktops, but it’ll be nice.
The trouble is many of the claims are being made by websites and then mirrored over many websites, often these claims are either misquotes or misunderstood entirely. For PC’s, DX12 will see the introduction of better multithreaded rendering, alongside several other needed features. For the Xbox One, for every fan claiming a huge performance boost there are those who’re claiming it’ll do nothing at all. Likely we’ll see the reality somewhere in the middle, with a nice increase in performance, but hardly earth shattering. There are certain DX12 features already implemented in the Xbox One version of DirectX, for more info check out our developers day breakdown.
The Ymmv (Your Mileage May Vary) is another key point – there’s often reason for conflicting reports from developers. Their goals and technology are different. Let’s assume there are two games, Game A and Game B. There are dozens of differences between their engines. But let’s say they are similar in they’re both created to be graphically impressive FPS titles so that the engines will at least behave ‘fairly similar’.
There are still multiple factors to consider regarding the performance and how much optimization, multi threading and other DX12 / low level API features will help (I won’t list them all, this is an example only). Which game engine, even if it’s say UDK – which version. Is it using a middlewear engine, if so which one and what version. How many enemies on screen at once. How complex is the AI, what was the lead development platform, how is physics being handled. What rendering technique is it using, how complex is lighting – what about texturing. How many objects are you trying to draw on screen at once?
In other words, various factors will massively impact how important low level optimizations are for your game, and what type of a boost. “Mantle gave our engine a 6x boost…” was clarified that is showing a lot of units simultaneously. Meaning lots of draw calls, lots of animation, lots of ‘stuff’ going on.
What this will mean for the Xbox One in the long term is hard to predict, but let’s be honest here, it’s going to be good for both PC and X1, and that’s the most important thing.