PCIe Bottlenecks Slash NVIDIA GeForce RTX 5090 Content Creation Performance by 25%

A lack of PCIe bandwidth can reduce RTX 5090 performance by as much as 25% in video editing and 3D workloads. Puget Systems conducted a series of tests on NVIDIA’s GeForce RTX 5090, comparing different PCIe versions and lane configurations to assess the impact on content creation tools. At its launch, TechPowerUp’s scaling tests noted that the GeForce RTX 5090 is the first high-end card to adopt PCIe 5.0 x16, delivering 64 GB/s of bidirectional bandwidth—twice the 32 GB/s that the RTX 4090 achieves on PCIe 4.0 x16. Our testing revealed a potential performance impact of up to 25% when utilizing limited PCIe bandwidth. Puget Systems today put this interface to the test, confirming real‑world impacts on video editing workflows when lanes or generations are constrained.

In DaVinci Resolve benchmarks, Puget Systems found that configurations running at PCIe 5.0 x16, PCIe 5.0 x8, or PCIe 4.0 x16 yielded virtually identical render times. Dropping to PCIe 5.0 x4, PCIe 4.0 x8, or PCIe 3.0 x16 introduced a modest 10% slowdown. Further reducing bandwidth to PCIe 4.0 x4 or PCIe 3.0 x8 resulted in an increase of roughly 25% in render times. After Effects exhibited only minor slowdowns once the bandwidth dropped below 8 GB/s. Unreal Engine 5.5 virtual production tests recorded about a 7% drop in average frame rates at the lowest lane counts. By contrast, Blender offline renders and OctaneBench scores remained essentially unchanged, and Llama LLM benchmarks showed no measurable dependency on PCIe speed.

The PCIe 5.0 on RTX 5090 employs the same NRZ signaling as PCIe 4.0 but incorporates stricter signal integrity measures, including decision feedback equalization and tighter timing controls. Although fully backward compatible with PCIe 4.0, 3.0, and even older standards, the RTX 5090’s massive bandwidth headroom raises the question of how much performance is lost on legacy slots or when lanes are shared with NVMe drives. These findings reveal a common limitation of modern motherboards: most reserve full x16 lanes for a single slot, forcing any additional devices or drives to operate at half or quarter speed. As a result, a flagship GPU can unknowingly operate at PCIe 4.0 x4, extending project turnaround times for professionals working with high-resolution timelines or complex 3D scenes. For studios and power users planning multi-card configurations, the clear recommendation is to verify that the RTX 5090 remains in a full-bandwidth slot.