[SOLVED] What affects an external drives write speed?

[_dawn_chorus_]

-I bought a 5Tb external drive and am backing up everything and I noticed if I copy over a large 100gb folder full of files around 3gb each it will write to the external drive around100-130mbps. However if I copy over a 100gb folder full of small files that are kb in size it only writes at around 30mbps. Why does it seem writing many small files causes it to write slower?

- Also if I copy a group of folders, say Documents, Pictures, Music, and Videos, it estimates a time of like 8 hrs... but if I copy each folder over individually it only takes about 20-30 min a folder which does not add up to 8hr.. Why would copying the same amount of files and data take less time selecting them individually than as a group?

This is all from internal ssd's to an external hdd.

 

[mdd1963]

smaller files scattered around take longer, particularly for 5400 RPM drives..; you cannot /should not expect a constant 100-130 MB/sec for small writes, medium sized writes, etc...

Your numbers are likely where they should be...