Exploring DirectX 12: 3DMark API Overhead Feature Test
by Ryan Smith & Ian Cutress on March 27, 2015 8:00 AM EST- Posted in
- GPUs
- Radeon
- Futuremark
- GeForce
- 3DMark
- DirectX 12
Closing Thoughts
Wrapping things up, Futuremark’s latest benchmark certainly gives us a new view on DirectX 12, and of course another data point in looking at the performance of the forthcoming API.
Since being announced last year – and really, since Mantle was announced in 2013 – the initial focus on low-level APIs has been on draw call throughput, and for good reason. The current high-level API paradigm has significant CPU overhead and at the same time fails to scale well with multiple CPU cores, leading to a sort of worst-case scenario for trying to push draw calls. At the same time console developers have low enjoyed lower-level access and the accompanying improvement in draw calls, a benefit that is an issue for the PC in the age of so many multiplatform titles.
DirectX 12 then will be a radical overhaul to how GPU programming works, but at its most basic level it’s a fix for the draw call problem. And as we’ve seen in Star Swarm and now the 3DMark API Overhead Feature Test, the results are nothing short of dramatic. With the low-level API offering a 10x-20x increase in draw call throughput, any sort of draw call problems the PC was facing with high-level APIs is thoroughly put to rest by the new API. With the ability to push upwards of 20 million draw calls per second, PC developers should finally be able to break away from doing tricks to minimize draw calls in the name of performance and focus on other aspects of game design.
GDC 2014 - DirectX 12 Unveiled: 3DMark 2011 CPU Time: Direct3D 11 vs. Direct3D 12
Of course at the same time we need to be clear that 3DMark’s API Overhead Feature Test is a synthetic test – and is so by design – so the performance we’re looking at today is just one small slice of the overall performance picture. Real world game performance gains will undoubtedly be much smaller, especially if games aren’t using a large number of draw calls in the first place. But the important part is that it sets the stage for future games to use a much larger number of draw calls and/or spend less time trying to minimize the number of calls. And of course we can’t ignore the multi-threading benefits from DirectX 12, as while multi-threaded games are relatively old now, the inability to scale up throughput with additional cores has always been an issue that DirectX 12 will help to solve.
Ultimately we’re looking at just one test, and a synthetic test at that, but as gamers if we want better understand why game developers such as Johan Andersson have been pushing so hard for low-level APIs, the results of this benchmark are exactly why. From discrete to integrated, top to bottom, every performance level of PC stands to gain from DirectX 12, and for virtually all of them the draw call gains are going to be immense. DirectX 12 won’t change the world, but it will change the face of game programming for the better, and it will be very interesting to see just what developers can do with the API starting later this year.
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jtrdfw - Monday, April 6, 2015 - link
Actually it comes from terminator 2 when arnold is dropped into the molten metal.Zepid - Friday, March 27, 2015 - link
Not all 8GB is addressable. Only 3.5 GB of memory on the PS4 is, with 500MB extra of virtual in the wing. The Xbox One has 4GB addressable by the GPU, but a much weaker GPU.PlayStationBSD consumes a considerable amount of overhead, more than the HyperV Windows OS on the Xbox One.
Source: Console development at EA.
Laststop311 - Saturday, March 28, 2015 - link
yea ur right 4GB max for xbox one and 4GB max for ps4 but only if they tap into the extra 500MB offeredSamus - Saturday, March 28, 2015 - link
DirectX is an API, ie, software. There is nothing stopping Microsoft ans Sony from enabling DX12 in their consoles ans updating the devkits.DERSS - Saturday, March 28, 2015 - link
Sony obviously can not have anything to do with DX12, but nor they have to in the first place -- AMD's Mantle transitions to OpenGL's Vulkan project, so all games that are OpenGL-bases will be able to use it. Before that, AMD can help with using pure Mantle on PS4 as standalone thing as it is their GPU in there anyway.Gigaplex - Monday, March 30, 2015 - link
Sony could, if they managed to licence the API. There is no technical limitation preventing them from porting the DirectX API.akamateau - Thursday, April 30, 2015 - link
Actually SOny would have some difficulty as they are not using a Windows kernal as Microsoft is doing.PS4 uses Orbis OS derived from FreeBSD. DX12 obviously will not run on that though I am sure that Sony has that issue solved.
akamateau - Thursday, April 30, 2015 - link
Nah....DX12 is going into XBOX probably by October.http://www.vrworld.com/2015/04/29/directx-12-on-xb...
Current XBOX games will see a performance boost but the greatest boost will happen when XBOX game developers start writing DX12 games.
imaheadcase - Friday, March 27, 2015 - link
You also deal with the terrible UI in games for console users. Many small things in games add up to major complains for PC users.Frenetic Pony - Friday, March 27, 2015 - link
This is somewhat accurate. With DX12/Vulcan games should actually be easier to port, as explicit memory control, tight thread controls, and cheap draw calls are all assumed to be there when writing for consoles, which is then code beaten repeatedly like an abused step child to get it to play nice with DX11, in most part because it's not known what exactly the API and card are actually doing together.The end result should actually be that minimum requirements to play games, which crept up a lot over the last generation as the consoles were better understood but the PC version had to be brute forced into getting the API to behave, should creep up a lot less. But considering both the CPU and GPU of a high end PC are far beyond both consoles already, I'm not sure how much benefit end users will directly see. Maybe there will be setting to stop culling out small objects with distance, that would be an easy abuse of all those extra draw calls. But otherwise I can see the low to mid end benefitting a lot more than someone running crossfire 390s or something.