NVMe SSD

NVMe (Non-Volatile Memory Express) is the storage protocol designed for SSDs from the ground up, in contrast to AHCI/SATA which was designed for spinning disks.

PCIe generations

• PCIe 3.0 x4 — ~3.5 GB/s read. Mid-2020s baseline.
• PCIe 4.0 x4 — 7 GB/s. Current sweet spot.
• PCIe 5.0 x4 — 14 GB/s. Top tier; runs hot.

Real-world impact

Game level-load times: PCIe 4 is meaningfully faster than SATA; PCIe 5 is rarely faster than PCIe 4 in games because the workload is random reads, not sequential. PCIe 5 shines in video editing scratch disks and 3D asset loading.

DRAM-less vs DRAM-cached

Budget NVMe SSDs omit the DRAM cache to save cost. Acceptable for OS drives; noticeably slower under sustained writes (large file transfers, video render).