Gbps

Gbps (gigabits per second) equals 1,000 Mbps. Residential gigabit plans (1 Gbps) are now mainstream from fiber ISPs including AT&T Fiber, Verizon Fios, and Google Fiber. Multi-gig plans (2–10 Gbps) are emerging but require specialised hardware.

Gbps, Mbps, and Kbps: the conversion table

Bits vs bytes — why the numbers look different

Internet speeds are measured in bits per second (lowercase b: Mbps, Gbps). File sizes are measured in bytes (uppercase B: MB, GB). One byte equals 8 bits. This is why a 1 Gbps connection does not transfer 1 GB per second of file data — it transfers 1,000 Mb/s ÷ 8 = 125 MB/s of actual file content (before protocol overhead). A 10 GB file at a sustained 125 MB/s would take 80 seconds, not 10. ISPs advertise speeds in bits; download managers show progress in bytes. When comparing the two, always divide the bit-rate by 8 to get the byte-rate.

Real-world activities requiring Gbps speeds

How gigabit internet reaches homes

GPON fiber (Gigabit Passive Optical Network) is the most common delivery technology for residential gigabit. A single fiber strand is split passively among 32–64 subscribers using optical splitters. Each subscriber gets a dedicated wavelength slice with up to 2.5 Gbps downstream and 1.25 Gbps upstream shared across the split ratio. XGS-PON upgrades this to 10 Gbps symmetrical shared capacity. DOCSIS 3.1 delivers gigabit over existing cable coax infrastructure using OFDM channels up to 192 MHz wide. In practice, DOCSIS 3.1 cable gigabit plans are asymmetric (typically 35–50 Mbps upload). Active Ethernet (point-to-point fiber) gives each subscriber a dedicated fiber strand with full 1–10 Gbps symmetric capacity — used by some smaller fiber providers and business services.

Multi-gig Ethernet: 2.5G, 5G, and 10G

Standard Gigabit Ethernet (1GbE) has been the home networking standard since the mid-2000s, but ISPs are now offering 2 Gbps and higher plans. These require multi-gig Ethernet throughout your home network. 2.5GbE runs over the same Cat5e/Cat6 cable as 1GbE and is the most practical upgrade for most homes — routers, switches, and USB adapters with 2.5GbE are widely available and affordable. 5GbE also runs over Cat5e/Cat6 up to 100m. 10GbE requires Cat6A for runs over 55m and is currently found primarily in high-end routers and network switches. Most Wi-Fi 6E routers include a 2.5GbE WAN port; routers designed for multi-gig plans increasingly include 10GbE WAN ports.

Overhead: why real file transfer is slower than the Gbps number suggests

Even on a perfect 1 Gbps connection, you will never see 125 MB/s of sustained file transfer for several reasons. TCP/IP protocol headers add 2–5% overhead. TCP slow start means the connection ramps up gradually rather than hitting full speed instantly. The remote server's upload bandwidth or disk I/O may be the bottleneck, not your download speed. File system overhead on your local drive (especially with many small files) can limit write speed. And Wi-Fi introduces additional overhead that reduces throughput to 50–80% of the wired rate. The practical sustained file transfer rate on a wired gigabit connection is typically 90–115 MB/s to a well-provisioned server.

Do you actually need gigabit?

For most households: probably not yet. A 500 Mbps plan handles 4K streaming on multiple TVs, video calls, gaming, and cloud backups simultaneously with headroom. Gigabit becomes worth the premium when you regularly transfer large files, run a home server, or have 8+ simultaneous heavy users. The strongest argument for gigabit is future-proofing and the fact that, on fiber, gigabit symmetric plans often cost only marginally more than 500 Mbps plans.

Hardware limits at gigabit speeds

To actually see 1 Gbps on a speed test, every link in the chain needs to support it: your router's WAN port, the Ethernet cable (Cat5e minimum, Cat6 recommended), and your device's NIC. Most laptops have a 1 GbE port that caps at ~940 Mbps real-world. For 2.5 Gbps+, you need a 2.5GbE or 10GbE NIC.

Frequently Asked Questions

Is 1 Gbps overkill for a home?

For most homes today, yes. The practical ceiling for a household of 4–6 people doing 4K streaming, gaming, and video calls is around 300–500 Mbps. Gigabit is future-proof and justifiable if the price difference is small.

What router do I need for gigabit internet?

Any router with a gigabit WAN port — which includes most routers sold after 2015. The bottleneck is usually Wi-Fi, not the router's WAN port. For Wi-Fi 6 or 6E, look for routers that support 2.5 GbE WAN if you are on a multi-gig plan.