PCIe Gen Roadmap for SSDs

Overview

The PCIe generation roadmap for SSDs tracks both increasing storage bandwidth (needed to feed advancing GPU architectures) and rising per-device power requirements that are forcing the industry transition from air to liquid cooling. As presented at OCP Global Summit 2025: PCIe 4.0 (~23W, 2020), PCIe 5.0 (~25W, 2022-2024), PCIe 6.0 (~40W projected, ~2026), and PCIe 7.0 (60-70W projected) form the progression.

PCIe Gen 5 at ~25W already places most common SSD form factors (E1.S 9.5mm, E1.S 15mm, E3.S) at or above the ASHRAE A2 35°C inlet air temperature limit. At PCIe Gen 6 (~40W), air cooling becomes impractical without unacceptable OPEX cost (lower data center air temperatures) or rack space penalties (larger heat sinks). At PCIe Gen 7 (60-70W), air cooling is definitively infeasible. The storage bandwidth scaling is not optional — MLCommons MLPerf Storage 2.0 data shows a linear relationship between storage read bandwidth and GPU utilization, making storage performance a direct determinant of AI cluster economics.