DirectX 12 boosts performance of HITMAN 2

May 14th, 2019

Our partners at IO Interactive, the developers of the award-winning HITMAN franchise, recently added DirectX 12 support to HITMAN 2, with impressive results. IO Interactive was so excited that they wanted to share a bit about how their innovative use of DirectX 12 benefits HITMAN gamers everywhere.

The guest post below is from IO Interactive:

DirectX 12 boosts performance of HITMAN 2

by Brian Rasmussen, Technical Producer, IO Interactive

With the latest update HITMAN 2 is available for DirectX 12 and users report improved performance in many cases. HITMAN 2 is a great candidate for taking advantage of DirectX 12’s ability to distribute rendering across multiple CPU cores, which allows us to reduce the frame time considerably in many cases. The realized benefits depend on the both the game content and the available hardware.

In this post, we look at how HITMAN 2 uses DirectX 12 to improve performance and provide some guidelines for what to expect.

Highly detailed graphics requires both CPU and GPU work

Figure 1 – The Miami level in Hitman 2 benefits greatly from the multithreaded rendering in DirectX 12

HITMAN 2 levels such as Miami and Mumbai are set in highly detailed environments and populated with big crowds with multiple interaction systems that react intelligently to the player’s actions.

Rendering these game levels often requires more than ten thousand draw calls per frame. This easily becomes a CPU bottleneck as there’s not enough time in a frame to submit all the draw calls to the GPU on a single threaded renderer.

DirectX 12 allows draw calls to be distributed across multiple threads which allows the game engine to submit more rendering work than previously possible. This improves the frame time of exciting game levels and allows us to create new content with even higher level of details in the future.

With its big crowds and complex AI HITMAN 2 is very CPU intensive, so we have built an architecture that allows us to take advantage of the available hardware resources. The Glacier engine powering HITMAN 2 uses a job scheduler to distribute CPU workloads across the available cores, so we already have the necessary engine infrastructure to take advantage of DirectX 12.

Multithreaded rendering

With DirectX 12 we can use the job scheduling mechanism of our game engine to distribute rendering submissions across available CPU cores. For complex game levels this offers substantial reductions in the time needed to submit rendering to the GPU and consequently reduces the frame time significantly.

The graph below shows results from one of our internal stutter analysis performance tests. Vertically it shows frame time (lower is better) and horizontally it shows percentiles for the performance samples. For DirectX 11, 99% of the captured frames rendered in 28.2ms or less on this hardware, and for DirectX 12, 99% of the captured frames rendered in 20.1ms.

The graph shows a significant reduction of the frame time across all the samples leading to a much smoother game experience. For instance, based on the numbers above the game rendered at 35 FPS 99% of the time on DirectX 11. On DirectX 12 this increases to 50 FPS, or close to a 43% improvement.

Figure 2 – The DirectX 12 version of HITMAN 2 shows consistently reduced frame time on complex game levels

The data was gathered on a 6 core Haswell CPU with an AMD Fury X GPU. We expect to see performance improvements on PCs with a similar or better GPU and at least four available CPU cores.

For less capable systems we recommend staying with the DirectX 11 version of HITMAN 2. Our DirectX 11 implementation offers slightly better performance on lower end systems. DirectX 12 requires additional work on the part of the game, so in some cases the overhead of this may result in poorer performance compared to the DirectX 11 version. We are still optimizing our DirectX 12 implementation and we expect to see improved performance on additional configurations, but currently DirectX 11 may be the best option for players with less capable systems.

We hope this new version of HITMAN 2 provides a better experience for some players and look forward to hearing your feedback.