Megabyte per second to Gibibyte per second

Many USB drives use a small SLC cache for initial writes at high MB/s, then slow dramatically once the cache fills and data writes to slower TLC/QLC NAND. A drive that starts at 200 MB/s might drop to 20–30 MB/s after the first few gigabytes. Check sustained write speed reviews, not just peak numbers.

Editing 4K ProRes footage requires about 200–400 MB/s of sustained read speed. 8K RAW can demand 1,000+ MB/s. A SATA SSD (550 MB/s) handles 4K fine, but 8K workflows really need NVMe drives at 3,000+ MB/s. The timeline scrubbing experience directly correlates with MB/s.

Look at the capitalisation: lowercase "b" (Mbps) means megabits, uppercase "B" (MB/s) means megabytes. Most speed test websites (Speedtest by Ookla, fast.com) default to Mbps. If your result seems 8× lower than expected, you are probably reading MB/s where you expected Mbps.

PCIe 5.0 NVMe SSDs hit 12,000–14,000 MB/s sequential read speeds. That is fast enough to load an entire 50 GB game in about 4 seconds. PCIe 6.0 drives, expected soon, will double this again to roughly 25,000 MB/s.

Network transfers add latency, protocol overhead (SMB, NFS), and are limited by the network link speed. A file on a local NVMe SSD reads at 7,000 MB/s, but sharing it over a 1 Gbps network caps throughput at 125 MB/s. Even 10 GbE only gives 1,250 MB/s — a fraction of modern SSD capability.

GPU memory is addressed in binary (power-of-2 bus widths like 256-bit or 384-bit), so binary units naturally describe the actual hardware capability. Some vendors use GiB/s to be precise, while marketing materials prefer the larger-sounding GB/s number. The RTX 4090's 1,008 GiB/s is 1,082 GB/s — the latter sounds faster.

DDR5-6000 in dual-channel mode provides about 93 GiB/s (100 GB/s). Quad-channel DDR5 on workstation platforms doubles this to ~186 GiB/s. The actual usable bandwidth depends on memory access patterns — random access achieves far less than sequential streaming.

Memory bandwidth (50–100+ GiB/s for DDR5) measures how fast the CPU can read/write RAM. Storage bandwidth (3–14 GiB/s for NVMe SSDs) measures persistent data transfer. Memory is 10–30× faster because DRAM has nanosecond latency while NAND flash has microsecond latency. They serve different roles in the data hierarchy.

Yes. For memory bandwidth, run a STREAM benchmark (available for Linux and Windows). For storage, use fio or CrystalDiskMark. GPU memory bandwidth can be tested with gpu-burn or vendor-provided tools. All will report in either GiB/s or GB/s depending on the tool — check which one.

Electrical signalling on copper traces maxes out around 112 Gbps (about 13 GiB/s) per lane with current technology. Beyond that, optics take over — silicon photonics interconnects can push individual channels to 200+ Gbps. The physical speed of light in fiber is not the limit; it is the modulation and detection electronics.