How long does it take to write 100 GB to a Gen4 NVMe SSD? Cache and cooling limits

Writing 100 GB to a PCIe 4.0 NVMe SSD at the interface's ~7 GB/s (56 Gbps) peak works out to 14 seconds. It's the fastest consumer storage transfer you can do, and it's the benchmark speed to compare portable/external drives against when evaluating their real performance.

Transfer time

14s

At peak link speed

File size

100 GB

Link speed

56,000 Mbps

PCIe 4.0 NVMe (~7 GB/s)

Configuration

File Size

Connection Speed

Mbps

Estimated Transfer Time

14s

Speed Comparison

USB 2.0

27m 46s

480 Mbps

USB 4 / Thunderbolt 4

20s

40 Gbps

Gigabit Ethernet

13m 20s

1 Gbps

10 Gigabit Ethernet

1m 20s

10 Gbps

WiFi 5 (ac)

33m 20s

400 Mbps

WiFi 7 (be)

2m 40s

5 Gbps

SATA SSD

3m 1s

4.4 Gbps

NVMe Gen4 SSD

14s

56 Gbps

How this is calculated

Real-world Gen4 NVMe sustained write performance drops sharply once the drive's SLC cache fills, typically after 50-150 GB written depending on drive capacity. A 1 TB 980 Pro holds the full 7 GB/s for about the first 100 GB, then drops to roughly 1.6 GB/s native TLC speed, extending the 100 GB transfer to more like 40-50 seconds if the cache is already partly used. PCIe 5.0 NVMe doubles the peak to ~14 GB/s, cutting this to 7 seconds under ideal conditions.

Verdict

14 seconds is the best-case figure for 100 GB on a fresh Gen4 SSD. It illustrates why upgrading from SATA SSD (3 minutes) to NVMe is transformative for workflows that move large files frequently.