A unit of data transfer rate equal to 1,000,000,000 bits (10⁹ bits), usually written as Gbit/s (gigabits per second).
Key conversion: 1 Gbit/s ≈ 125 MB/s theoretical (divide by 8); real-world throughput is almost always lower due to protocol overhead.
Major real-world examples across all common technologies (approximate usable speeds after overhead):
| Advertised speed | Theoretical max | Typical Throughput | Common Technologies |
|---|---|---|---|
| 1 Gbit/s | 125 MB/s | ~110–125 MB/s | Gigabit Ethernet, Wi-Fi 4 (3×3), early Bluetooth 5 |
| 2–2.5 Gbit/s | 250–312 MB/s | ~230–310 MB/s | 2.5Gb Ethernet, Wi-Fi 6 (80 MHz 2×2) |
| 3 Gbit/s | 375 MB/s | ~280–300 MB/s | SATA II |
| 4G LTE-Advanced | up to ~1–3 Gbit/s peak | ~50–500 Mbit/s | Cellular 4G (Cat 16–20) |
| 5 Gbit/s | 625 MB/s | ~570–620 MB/s | 5Gb Ethernet, USB 3.2 Gen 2×1 |
| 5G NR (sub-6) | up to ~10 Gbit/s peak | ~300 Mbit/s – 2 Gbit/s | Cellular 5G mid-band |
| 6 Gbit/s | 750 MB/s | ~550–600 MB/s | SATA III (most common SATA) |
| 8–9.6 Gbit/s | 1–1.2 GB/s | ~900 MB/s – 1.1 GB/s | Wi-Fi 6/6E 160 MHz 2×2, PCIe 3.0 ×1 |
| 10 Gbit/s | 1.25 GB/s | ~1.1–1.25 GB/s | 10Gb Ethernet, USB 3.2 Gen 2×2, 5G mmWave peaks |
| ~20–30 Gbit/s | 2.5–3.75 GB/s | ~2–3.5 GB/s | Wi-Fi 6E/7 320 MHz 2×2–4×4 real-world |
| 32 Gbit/s | 4 GB/s | ~3.6–3.94 GB/s | PCIe 4.0 ×2, mainstream NVMe SSDs |
| 40 Gbit/s | 5 GB/s | ~4.5–4.8 GB/s | 40Gb Ethernet, Wi-Fi 7 320 MHz 4×4 peaks |
| 64 Gbit/s | 8 GB/s | ~7–7.8 GB/s | PCIe 4.0 ×4 / PCIe 5.0 ×2 (high-end NVMe SSDs) |
| 100 Gbit/s | 12.5 GB/s | ~11–12 GB/s | 100Gb Ethernet, datacenter networking |
| 128 Gbit/s | 16 GB/s | ~14–15.7 GB/s | PCIe 5.0 ×4 (fastest current consumer SSDs) |
Whenever you see a speed advertised in Gbit/s, whether it’s wired Ethernet, Wi-Fi, USB, SATA, PCIe, or even Bluetooth — divide by about 8–10 to get a realistic idea of the megabytes per second you’ll actually experience.