Gigabyte per second to Terabit per second

CPUs constantly shuttle data between RAM and their caches. DDR5-6000 provides about 96 GB/s of bandwidth in dual-channel mode. In games, insufficient RAM bandwidth causes frame drops during complex scenes. In productivity tasks like video encoding, it directly limits how fast the CPU can process data.

Thunderbolt 4 runs at 40 Gbps, which is 5 GB/s. Thunderbolt 5, released in 2024, doubles this to 80 Gbps (10 GB/s) with a burst mode up to 120 Gbps (15 GB/s). This is fast enough to run an external NVMe SSD at near-internal speeds.

Both, depending on generation. A PCIe 3.0 ×4 interface caps at ~3.5 GB/s, bottlenecking modern NAND. PCIe 4.0 ×4 raises this to ~7 GB/s, and PCIe 5.0 ×4 to ~14 GB/s. The drive's NAND flash and controller also have limits — the fastest SSDs and the fastest interfaces are in a constant leapfrog.

GPUs use wide memory buses (256–384 bits) with very fast HBM or GDDR6X memory running at high clock speeds. An RTX 4090 has a 384-bit bus with GDDR6X at 21 Gbps per pin, totalling 1,008 GB/s. HBM3 in data center GPUs achieves 3,000+ GB/s through stacked memory with 4096-bit buses.

At multi-GB/s rates, CPU processing speed, software efficiency, and thermal throttling become bottlenecks. A 14 GB/s PCIe 5.0 SSD can deliver data faster than most applications can consume it. Decompression, parsing, and memory allocation in software often cannot keep up with raw storage bandwidth.

Global internet traffic peaks at roughly 1,000–1,500 Tbps (1–1.5 Pbps) as of 2026. This is growing at about 25% per year, driven by video streaming, cloud computing, and AI training data transfers. A single viral live event can spike regional traffic by tens of Tbps.

Internet traffic automatically reroutes through other cables and paths via BGP routing protocols, usually within seconds. Speed may degrade in the affected region but rarely drops entirely. Cable cuts happen more often than people think — about 100 per year globally, mostly from ship anchors and fishing trawlers.

Dense wavelength-division multiplexing (DWDM) sends dozens of different light colors (wavelengths) through a single fiber simultaneously, each carrying its own data stream. A modern cable contains multiple fiber pairs, each carrying 100+ wavelengths, with each wavelength modulated at 400 Gbps or more.

Netflix's library is estimated at around 30–40 petabytes. At 1 Tbps, downloading the entire catalog would take roughly 70–90 hours. At 100 Tbps (a realistic submarine cable capacity), you could theoretically grab all of Netflix in under an hour.

Researchers at Japan's NICT achieved 22.9 Pbps (22,900 Tbps) through a single multicore fiber in 2024. That is enough to transfer the entire Library of Congress in a fraction of a second. These lab records typically reach commercial deployment 5–10 years later.