Megabit per second to Kibibyte per second

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.

Rsync follows IEC binary conventions because it deals with file sizes that are measured in binary units by the filesystem. Since files occupy whole filesystem blocks (typically 4 KiB), reporting transfer speed in KiB/s makes the math consistent with actual data moved on disk.

1 KiB/s (1,024 bytes/second) is 2.4% faster than 1 kB/s (1,000 bytes/second). The difference is tiny at this scale but matters when you are designing buffer sizes for embedded systems where every byte of RAM counts.

Microsoft started using binary units more consistently in Windows 10 after years of ambiguity where "KB" sometimes meant 1,000 and sometimes 1,024 bytes. The shift toward KiB follows IEC recommendations and reduces confusion, though the transition is still incomplete across all Windows tools.

A 3.5-inch floppy drive transferred data at about 31–62 KiB/s (250–500 kbps). Copying a full 1.44 MB floppy took roughly 25–50 seconds. For comparison, a modern NVMe SSD is about 100,000 times faster.

In embedded systems with tight memory constraints, confusing 1,024 with 1,000 can overflow a buffer. In network protocols, a spec written in KiB/s being implemented as kB/s means transmitting 2.4% less data than expected per second — enough to cause timing violations in real-time systems.