JBX PCIE BENCHMARK BLOG PCIe 4.0 vs 5.0 GPUs
PCIe 4.0 vs 5.0 GPUs
GPU Architecture • 6 Min Read

PCIe 4.0 vs. PCIe 5.0 GPUs: Gaming Performance

By JBX Tech Experts • Published August 2026

Understanding Bus Bandwidth Saturation

PCIe Gen 5 doubles maximum slot bandwidth to 64 GB/s over 16 lanes compared to 32 GB/s on PCIe Gen 4. But does this extra bandwidth impact actual in-game frame rates?

1. Benchmark Results (RTX 4090 / RTX 4080)

Current flagship graphics cards operating at PCIe 4.0 x16 utilize only 60-70% of available Gen 4 bandwidth. FPS benchmarks at 1440p and 4K show less than 1-2% difference between Gen 4 and Gen 5 slots.

2. Where PCIe 5.0 Matters Most

PCIe Gen 5 provides significant advantages when using GPUs running in x8 or x4 lane configurations, or when leveraging DirectStorage texture streaming from PCIe Gen5 NVMe SSDs.

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