USB Write Time for 7.34 GB File | Generated by AI
Question: Suppose the iOS file (or ISO) is 7.34 GB, then how much time do I need to wait based on my previous dd write speeds?
Answer:
Your previous dd write to the USB drive showed these speeds:
- Early/middle phase: roughly 20–21 MB/s
- Later phase / overall average: around 15.5 MB/s
We’ll calculate the expected time for a 7.34 GB file using both speeds (real-world USB write usually slows a bit toward the end, so the lower number is more realistic).
Calculations
1 GB = 1,000,000,000 bytes (using the decimal definition most people expect for file sizes and download times)
7.34 GB = 7,340,000,000 bytes
| Speed | Bytes per second | Time in seconds | Time in human-readable format |
|---|---|---|---|
| 20.8 MB/s | 20,800,000 | ≈ 353 seconds | ≈ 5 minutes 53 seconds |
| 20.0 MB/s | 20,000,000 | ≈ 367 seconds | ≈ 6 minutes 7 seconds |
| 15.5 MB/s | 15,500,000 | ≈ 474 seconds | ≈ 7 minutes 54 seconds |
Realistic estimate
- Best case (if your USB maintains ~20–21 MB/s the whole way): about 5.5–6 minutes
- Most likely case (based on your actual final average): about 7.5–8.5 minutes
- Worst case (if it drops more due to thermal throttling, cache flush, or USB controller): 9–11 minutes
So for a 7.34 GB file written to the same USB drive with dd … bs=1m, you should expect to wait roughly 7 to 9 minutes.
Tips to possibly make it faster:
- Use a USB 3.0/3.1 port if you’re not already
- Try a different (newer/faster) USB flash drive
- Use Etcher, Rufus, or Ventoy instead of raw
dd— they sometimes manage caching and I/O better
References:
- None (calculation based on your provided dd output)