Kilobyte per second to Mebibyte per second
KBps
MiBps
Conversion History
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Quick Reference Table (Kilobyte per second to Mebibyte per second)
| Kilobyte per second (KBps) | Mebibyte per second (MiBps) |
|---|---|
| 1 | 0.00095367431640625 |
| 7 | 0.00667572021484375 |
| 56 | 0.05340576171875 |
| 128 | 0.1220703125 |
| 512 | 0.48828125 |
| 1,000 | 0.95367431640625 |
About Kilobyte per second (KBps)
A kilobyte per second (kB/s or KBps) equals 8,000 bits per second and was the standard unit for measuring file download speeds in the dial-up and early broadband era. Download managers throughout the 1990s and 2000s displayed speeds in kB/s — a 56 kbps modem delivered about 7 kB/s, while early ADSL connections reached 256–512 kB/s. The unit remains useful for describing very slow links such as SMS data, GPRS connections, and low-speed serial interfaces.
A 56 kbps dial-up modem transferred files at roughly 7 kB/s. GPRS mobile data (2G) typically achieved 20–40 kB/s.
About Mebibyte per second (MiBps)
A mebibyte per second (MiB/s) equals 1,048,576 bytes per second and is the binary unit most commonly seen in operating system disk and memory bandwidth reports. Linux tools like dd, rsync, and hdparm report I/O speeds in MiB/s. Windows Task Manager and Resource Monitor use MB/s, which is decimal. A USB 2.0 high-speed connection peaks at about 60 MiB/s; a SATA SSD reads at 500–600 MiB/s; an NVMe SSD reaches 3,500–7,000 MiB/s.
Running dd on Linux to test disk speed shows results in MiB/s. A SATA III SSD typically reads at around 550 MiB/s.
Kilobyte per second – Frequently Asked Questions
How long did it take to download a song on dial-up at 7 kB/s?
A typical 4 MB MP3 file at 7 kB/s took about 9–10 minutes to download. Napster users in 1999 would queue up songs before bed and hope the phone line stayed connected overnight. A single disconnection meant starting over from scratch.
What is the difference between kB/s and KB/s?
Lowercase "k" with uppercase "B" (kB/s) means 1,000 bytes per second (SI decimal). Uppercase "K" with uppercase "B" (KB/s) traditionally meant 1,024 bytes per second (binary). In practice, most software uses them interchangeably, and the difference is only 2.4%.
Why do some apps still show download speeds in kB/s?
Apps display kB/s when transfer speeds are genuinely that slow — downloading over congested mobile networks, tethering in rural areas, or transferring tiny files where the connection never ramps up. It is also common in SSH/SCP transfers that display instantaneous speed during small file copies.
How fast was early ADSL compared to dial-up in kB/s?
The first consumer ADSL plans offered 256 kbps downstream, delivering about 32 kB/s — roughly 4.5× faster than a 56k modem. A 512 kbps plan gave 64 kB/s. That first jump from 7 to 32 kB/s felt revolutionary, cutting a 10-minute download to about 2 minutes.
What speed do text messages transfer at in kB/s?
An SMS is limited to 140 bytes (160 characters in GSM-7 encoding), and the signalling channel transmits it almost instantly. But if you think of SMS throughput over a sustained period, the practical rate is about 0.1–0.5 kB/s because of the overhead between messages.
Mebibyte per second – Frequently Asked Questions
Why does dd report in MiB/s while manufacturers advertise in MB/s?
dd uses binary units because Linux filesystems work in binary block sizes (4 KiB, etc.). Drive manufacturers use decimal MB/s because it makes speeds look about 5% higher and aligns with their decimal capacity marketing. A "550 MB/s" SSD shows roughly 524 MiB/s in dd.
How do I benchmark my disk speed in MiB/s on Linux?
Run "dd if=/dev/zero of=testfile bs=1M count=1024 oflag=direct" and it will report write speed in MiB/s. For read speed, use "dd if=testfile of=/dev/null bs=1M". The oflag=direct flag bypasses filesystem cache to measure actual disk performance.
Is 550 MiB/s the same as 550 MB/s?
No — 550 MiB/s is about 577 MB/s, and 550 MB/s is about 524 MiB/s. The ~5% difference means an SSD advertised at 550 MB/s will show around 524 MiB/s in Linux tools. It is not a defect or false advertising, just different unit systems measuring the same physical speed.
What MiB/s should I expect from a RAID array?
A RAID 0 stripe of two SATA SSDs gives roughly 1,000–1,100 MiB/s sequential reads. Four NVMe SSDs in RAID 0 can hit 12,000–14,000 MiB/s. RAID 5/6 arrays sacrifice some write speed for redundancy — expect 70–90% of raw stripe performance on writes.
Why is random I/O speed so much lower than sequential MiB/s?
Sequential reads let the drive stream data from contiguous locations, maximising throughput. Random I/O forces the controller to seek different addresses, adding latency per operation. An NVMe SSD might do 7,000 MiB/s sequential but only 50–80 MiB/s random (at 4 KiB block size), because the bottleneck shifts from bandwidth to IOPS.