Gigabyte per second to Megabit 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.

Because ISPs advertise in megabits (Mb) while download managers show megabytes (MB). There are 8 bits in a byte, so 100 Mbps ÷ 8 = 12.5 MB/s. Your connection is working perfectly — it is just a unit mismatch that has confused people for decades.

Netflix recommends 25 Mbps for 4K, YouTube suggests 20 Mbps, and Apple TV+ needs about 25 Mbps. In practice, 50 Mbps gives comfortable headroom for one 4K stream plus normal browsing. A household streaming on multiple devices simultaneously should aim for 100+ Mbps.

Wi-Fi shares bandwidth among all connected devices, loses throughput to interference from walls and other electronics, and uses half-duplex communication (it cannot send and receive simultaneously). A 300 Mbps Wi-Fi router might deliver 100–150 Mbps to a single device in practice, while Ethernet gives you the full rated speed.

Download Mbps measures data coming to you (streaming, browsing), while upload Mbps measures data you send (video calls, cloud backups). Most home connections are asymmetric — 100 Mbps down but only 10–20 Mbps up. Fiber-to-the-home plans increasingly offer symmetric speeds.

Surprisingly little — most online games use only 1–3 Mbps of bandwidth. What gamers actually need is low latency (ping), not high throughput. A 10 Mbps connection with 15ms ping will outperform a 500 Mbps connection with 100ms ping for gaming every time.