Introduction

The NVIDIA GeForce RTX 5090, powered by the Blackwell architecture, sets a new benchmark in GPU technology—not just for performance. With its adoption of the PCI-Express 5.0 x16 interface, a first for a high-end graphics card, the RTX 5090 achieves an incredible 64 GB/s of bidirectional bandwidth, a dramatic improvement over the RTX 4090's PCIe 4.0 x16 bandwidth of 32 GB/s. This substantial leap can offer significant benefits for gaming, professional workloads, and data-intensive tasks, enabling smoother performance and faster data transfers.



While PCIe 5.0 unlocks the GPU's full potential, the RTX 5090 remains backward compatible with earlier PCIe generations, such as PCIe 4.0, 3.0, and even 2.0 and 1.1. This compatibility is invaluable for users with older systems, but it also prompts an essential question: how much does the PCIe interface impact performance?

In this article, we'll explore this by testing the RTX 5090 at different PCIe speed levels and bandwidths—from the latest PCIe 5.0 down to PCIe 1.0. By analyzing the GPU's performance across various scenarios, including gaming benchmarks at different resolutions, with RT disabled and enabled, we aim to determine the real-world impact of PCIe bandwidth on this next-generation graphics card.

From a technical perspective, PCI-Express 5.0 uses the same Non-Return-to-Zero (NRZ) signaling as PCIe 4.0 but implements stricter signal integrity measures to handle its doubled data rate of 32 GT/s per lane. Enhanced equalization techniques, like Decision Feedback Equalization (DFE), help counteract signal degradation and interference at these higher speeds. Additionally, tighter timing controls reduce jitter, ensuring reliable data transfer without the need for more complex signaling methods (like PAM3 or PAM4). These improvements allow PCIe 5.0 to achieve twice the bandwidth of PCIe 4.0 while maintaining compatibility with the same physical interface.

Our tests will help answer key questions for potential upgraders: is PCIe 5.0 essential to fully leverage the RTX 5090's power, or can older systems still deliver competitive performance with this cutting-edge GPU? What's the impact when an SSD eats half your PCIe lane budget? Can you run RTX 5090 in the bottom x16 slot at decent performance? Whether you're considering upgrading your system or simply curious about how much PCIe bandwidth influences modern GPUs, this analysis will provide detailed insights.

Read on as we dive into these performance tests and uncover how the NVIDIA GeForce RTX 5090 scales with various levels of PCI-Express bandwidth available.

Test System

Benchmark scores in other reviews are only comparable when this exact same configuration is used.

• All games and cards are tested with the drivers listed above—no performance results were recycled between test systems. Only this exact system with exactly the same configuration is used for all results in this review.
• All graphics cards are tested using the same game version.
• All games are set to their highest quality setting unless indicated otherwise.
• AA and AF are applied via in-game settings, not via the driver's control panel.
• Before starting measurements, we heat up the card for each test to ensure a steady state is tested. This ensures that the card won't boost to unrealistically high clocks for only a few seconds until it heats up, as that doesn't represent prolonged gameplay.
• For better real-life applicability, all game tests use custom in-game test scenes, not the integrated benchmarks.

Each game is tested at these screen resolutions:

• 1920x1080: Most popular monitor resolution.
• 2560x1440: Intermediary resolution between Full HD and 4K, with reasonable performance requirements.
• 3840x2160: 4K Ultra HD resolution, available on high-end monitors.

Date of Retest

We retest all our comparison cards every few months, with the latest drivers, new games, patches and OS updates.

• 2024-12-01: Arc A750 8 GB
• 2024-12-01: Arc A770 16 GB
• 2024-12-01: RTX 2080 Ti 11 GB
• 2024-12-01: RTX 3050 8 GB
• 2024-12-01: RTX 3060 12 GB
• 2024-12-02: RTX 3060 Ti 8 GB
• 2024-12-02: RTX 3070 8 GB
• 2024-12-02: RTX 3080 10 GB
• 2024-12-02: RTX 3090 24 GB
• 2024-12-03: RTX 4060 8 GB
• 2024-12-03: RTX 4060 Ti 8 GB
• 2024-12-03: RTX 4060 Ti 16 GB
• 2024-12-03: RTX 4070 12 GB
• 2024-12-04: RTX 4080 16 GB
• 2024-12-04: RTX 4090 24 GB
• 2024-12-04: RX 5700 XT 8 GB
• 2024-12-04: RX 6600 XT 8 GB
• 2024-12-05: RX 6700 XT 12 GB
• 2024-12-05: RX 6800 16 GB
• 2024-12-05: RX 6800 XT 16 GB
• 2024-12-06: RX 7600 8 GB
• 2024-12-06: RX 7600 16 GB
• 2024-12-06: RX 7700 XT 12 GB
• 2024-12-06: RX 7800 XT 16 GB
• 2024-12-07: RX 7900 XTX 24 GB

Alan Wake 2

Released: 2023 — API: DirectX 12 — Engine: Northlight

Alan Wake II, a survival horror sequel set 13 years after the original, follows FBI agent Saga Anderson investigating ritualistic murders in Bright Falls, Washington. Trapped in an alternate dimension, novelist Alan Wake crafts a horror narrative for escape, involving Saga. Players switch between Saga and Alan, balancing resources like batteries and ammunition. New features include detective elements, a dialogue tree system, and the "Mind Place" for investigation.