Quick test: DirectX 12 API Overhead Benchmark results
As you guys know, DirectX 12 is going to greatly free up processor utilization, and thus your games can make more draw-calls with your processor. More efficient usage of CPUs with multiple cores is trivial in the design. We can now test a thing or two out thanks to the 3DMark update released hours ago.
At this very moment with DirectX 11, no matter how many cores your CPU has, the first core does the majority of the hard work for the API, the rest of the cores doing very little. With DirectX 12 (and Mantle), the data-sets and this load will be better distributed and utilized meaning a far more efficient design usage, this removes certain CPU bottlenecks. DX12 is said to be capable of using as many as eight cores and hey, AMD has very nicely priced 8-core processors right ? But how can we test to see what is up and coming ?
Well, even you yourself can check that out @home now. If you own a 3DMark 2013 license and have Windows 10 preview build 10041 (free to download and install as it is a public preview) and have a compatible graphics card with DX12 enabled you can now test and see how huge that overhead always has been with 3DMark. Just make sure you update Windows 10 towards build 10041 which has DX12 support. For the graphics card drivers, wait for the Windows update. The Windows driver that install through the update are DX12 class compatible with respective Nvidia and AMD graphics cards.
The test works by tasking the GPU to draw something on the screen, literally this is what a draw call is, a request from the game engine on the processor to draw and render an object, period. This instruction goes through the API, that API would be DX11, DX12, or AMD's Mantle.
The less efficient the API is in handling the what we explained are "draw calls" from the CPU to the GPU, the fewer objects can be drawn on your monitor. 3DMark now has this test, and will speed up draw calls and objects until the frame rate drops under 30 frames per second (fps) and that is its equilibrium. The result is what we can show as the difference in number of draw calls per API. Our test has been performed at 1920x1080 (default is 1280x720 I think it was), just to make things a little heavier and more representative. Check out these numbers man, specifically in the jump from DX 11 towards Mantle and then DirectX 12. Mantle actually is a notch faster compared to DX12, still ... what a difference.
Intel Core i7-5960X (16 threads) / Radeon R9 290X
Our test system is absed on the following hardware:
- Intel Core i7-5960X (16 threads)
- AMD Radeon R9 290X
- MSI X99S XPower AC
- 16GB GSKILL DDR4-2133 Quad channel
- Corsair Force SSD
The difference in increase draw calls is going to be extraordinary positive. Obviously the results are relative to actual complex rendered frames and frame rates. But any old and or new processor will be utilized so much better. In the end the Windows 10 / DX12 combo is going to make a difference alright, yeah we are excited as man. Scene complexity with many more objects is going to rock hard. I mean overall we are looking at a 15 to 20x draw call increase on any mainstream to enthusiast class processor and what that can do with scene complexity will be very impressive. Also this means very good news for AMD and its APUs and FX processors as well as the entry level Intel CPU SKUs.
Yeah DirectX 12 could be a game-changer (literally) once widely adopted by the software houses, as such we feel this release is going to be EPIC. Go try it out yourself and let us know your results in the forums. You can download the updated 3DMark right here.
Senior Member
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Joined: 2006-11-10
I got ~ 1million draw calls boost by dx11 single threaded when going from 1333 9-9-9-24-2t (20gb/s, 65ns) to 2400 10-12-12-31-1t(36gb/s, 41ns)
By multi it was less, ~ 100k calls difference.. Still something

I see dx12 makes a nice boost
Oooh.. I am gonna have to test this on my x79 system with different RAM speeds.
Might as well set up a disk with Win10 as well to be able to do the DX12 tests.
And this is exactly why current and even older games seem smoother even if the framerate doesn't go up all that much when using really fast RAM.
Senior Member
Posts: 156
Joined: 2010-03-27
You've got a better one which will make it more interesting.
Senior Member
Posts: 10481
Joined: 2006-03-21
Hilbert, any chance you could test with high core count cpu with not great per core performance vs lower core count with great per core performance and with/without HT? e.g i7 4770K vs ancient Xeon 6 core 5660( just an example latest 8 core AMD is a cool alternative )
Point is, it would be good to see if DX12 removes the cpu race for the latest and greatest delivering higher per core performance vs older more slower core performance but higher core count.
Senior Member
Posts: 19558
Joined: 2010-04-21
I don't have 10 installed on anywhere other than VMware, and will not install it on real hardware while it's full of keyloggers and data collecting stuff, and in a very unfinished state
The guy wants results from an FX CPU and has an FX CPU
Senior Member
Posts: 6361
Joined: 2005-02-25
Via PCworld, some fun with TitanX : http://www.pcworld.com/article/2900814/tested-directx-12s-potential-performance-leap-is-insane.html
Something look strange on MT ( whatever it is Nvidia or AMD), depending the driver it seems. anyway this bench is not for compare gpu's, nor driver..but API on a certain similar test.