The video reveals that while Vulkan offers smoother frame pacing and better performance on GPUs with larger VRAM in Star Citizen’s 4.5 update, it struggles with stability and higher VRAM demands on mid-range and certain AMD and Intel systems, making DX11 still the more reliable choice for many users. Consequently, Vulkan is not yet ready to fully replace DX11, and both APIs are expected to coexist as Cloud Imperium Games continues to optimize Vulkan.
The video examines the performance differences between Vulkan and DirectX 11 (DX11) in Star Citizen following the 4.5 update, which brought significant Vulkan improvements. Testing was conducted across three systems and seven GPUs, revealing that Vulkan is not yet universally superior or ready to fully replace DX11. A major issue highlighted is VRAM usage; cards with only 6 GB of VRAM, such as the GTX 1660, struggle with Vulkan due to high memory demands, causing severe performance drops. For these users, DX11 remains the better choice, despite plans from Cloud Imperium Games (CIG) to eventually phase out DX11.
When using GPUs with larger VRAM, such as the RTX 3060 with 12 GB, Vulkan shows clear performance advantages over DX11, delivering smoother frame times and better overall gameplay experience. However, results are mixed for AMD cards; for example, the Radeon 5700 with 8 GB VRAM experienced crashes and instability under Vulkan. This inconsistency across different hardware configurations suggests that Vulkan still requires optimization and better compatibility before it can be considered a full replacement for DX11.
On mid-range systems, Vulkan tends to offer smoother frame pacing and better 1% low frame rates, which translates to a more consistent and enjoyable experience, especially when the CPU is the bottleneck. However, at higher resolutions like 1440p and 4K where the GPU is more heavily utilized, Vulkan appears to be more demanding on the GPU, sometimes resulting in lower average FPS compared to DX11. This suggests that while Vulkan reduces CPU load, it may increase GPU load, an area where CIG might need to focus future optimization efforts.
High-end hardware testing shows mixed results as well. On Intel-based systems, Vulkan often fails to launch or crashes, making DX11 the only viable option. Conversely, high-end AMD cards like the 7900 XT show Vulkan performing better, especially at lower resolutions where CPU bottlenecks are more pronounced. For top-tier Nvidia cards like the RTX 4080, Vulkan provides smoother performance at 1080p but falls behind DX11 at 4K. These variations underscore the complexity of Vulkan’s current implementation and the challenge of achieving consistent performance across diverse hardware.
In conclusion, while Vulkan brings notable improvements in smoothness and frame consistency, it is not yet a clear-cut replacement for DX11 in Star Citizen. Many users report positive experiences, but a significant number face crashes, instability, or worse performance depending on their hardware. Given these issues, it seems unlikely that CIG will remove DX11 support in the immediate future. Instead, both APIs will likely coexist for some time as CIG continues to refine Vulkan and address its current limitations.