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.
Facebook
Twitter
RSS
113 Comments
View All Comments
Laststop311 - Saturday, March 28, 2015 - link
The benefit will come mainly for people using chips with many cores but poorer single threaded performance. That's basically quad core AMD APU users and 8 core FX chip and 6 core phenom II x6. Since users of those cpu's are the people most likely to be CPU bottlenecked due to dx11 only caring about single thread performance. Since intel chips have top tier single threaded performance they were not as restricted in dx11 and the gpu was usually the bottleneck to begin with so not much change there the gpu will still be shader bound.silverblue - Saturday, March 28, 2015 - link
I'm glad somebody mentioned the Phenom II X6. I'd be very interested to see how it copes, particularly against the 8350 and 6350.akamateau - Thursday, April 30, 2015 - link
AMD A6 APU has 4.4 million draw calls per second running DX12. Intel i7 4560 and GTX980 only has 2.2MILLION draw calls running DX11!!!!DX12 allows a $100 AMD APU by itself to outperform a $1500 Intel/nVidia gaming system running DX11.
That is with 4 CORES. Single core performance is not relevant any more.
All things being equal, DX12 will give AMD APU and Radeon dGPU a staggering performance advantage over Intel/nVidia.
FlushedBubblyJock - Tuesday, March 31, 2015 - link
What's the mystery ? It's Mantle for everyone - that's what DX12 essentially is.So just look at what mantle did.
Close enough.
StevoLincolnite - Friday, March 27, 2015 - link
The consoles are limited to 6 cores for gaming, not 8, those 6 cores are roughly equivalent to a Haswell Core i3 in terms of total performance (Or a high clocked Pentium Anniversary!).Remember, AMD's fastest high-end chips struggles to beat Intel's 4 year old mid-range... Take AMD's low-end low-powered chips and it's a laughable situation.
But that's to be expected, consoles cannot afford to have high-end components, they are cost sensitive low-end devices.
Lets just hope that Microsoft and Sony do not beat this horse for all it's worth and we get a successor out within the next 4ish years.
The Xbox One also uses a modified version of Direct X 11 for it's high level API.
The Xbox One also has a low-level API which developers can target and extract more performance.
Basically once Direct X 12 is finalized for the PC it will be modified and ported to the Xbox One, giving developers who do not buy an already made game-engine like Unreal, CryEngine etc' a performance boost without blowing out development time significantly by being forced to target the low level API.
The same thing is also occurring on the Playstation, the high-level API is getting an overhaul thanks to Vulkan, it still has it's low-level API for developers to target of course.
Ram is still a bit of an issue too, 5-5.5Gb of Ram for the game and graphics is pretty tiny, it may become a real limiter in the coming years, slightly offset with hard drive asset streaming.
To compare it to a PC the Xbox One is like a Core i3 3ghz, 4Gb of Ram, Radeon 7770, 1.5Gb graphics card.
Change the GPU to a Radeon 7850 for the PS4 and that's what we have for the next half decade or more.
Laststop311 - Saturday, March 28, 2015 - link
Correct me if I'm wrong but I believe the ps4 is built with a downclocked 7870 (20 cu) but the ps4 igpu has 2 CU disabled as well as the downclock. The 7850 is a 16 CU part but i guess the 2 extra CU combined with the downclock would make the ps4 behave like a 7850. the radeon 7770 is only 10CU and the xbone has 12CU's but a lower clock. So are you basically saying for the ps4 and xbone the extra 2cu + the lower clock speed makes them equal to those desktop cards? Because they really aren't exactly those cards. Some situations the higher clock speed matters more and some the more cu's matter more. In some situations the ps4 may behave more like a 7870 than a 7850 and the xbone may be more like a 7790 than a 7770 in some situations.Gigaplex - Monday, March 30, 2015 - link
The console CPUs are actually significantly slower than a Haswell i3. The Pentium chips are a closer comparison due to the lack of hyperthreadingmr_tawan - Monday, March 30, 2015 - link
'PC is not meant to be played' (TM)(Just kidding though)
If the developers done their jobs right, hi-specs PC still gains much advantage over console (especially in the frame rate area). However PC itself are also a drag as well (remember those Atom/Pentium equipped PC).
JonnyDough - Tuesday, March 31, 2015 - link
Half the time it's just that they don't even bother updating menus and controls. Skyrim is a prime example.Veritex - Friday, March 27, 2015 - link
All the next generation consoles are based on AMD eight core CPU and GCN architecture (with Nintendo possibly opting for an ARM CPU paired with GCN), so developers will just have to optimize once for the consoles and have a easier time porting to PCs.It is interesting to see the AMD R9-285 Tonga consistently outperform Nvidia's high end GTX 980 and its make you wonder how incredibly fast the next generation R9-390x Fiji and 380x could be.