Slow USB backup speed - ReadyNAS Pro 6

Hi David_H, it could be related to the NTFS cluster size set to 512Bytes for whatever reason.

Under windows you can find out the current cluster size by executing as admin eg using powershell

fsutil fsinfo ntfsinfo X:

When formatting an NTFS hardisk you can choose how big the clusters should be to hold your data. The cluster size can range from 512 Bytes to 64 KBytes.

Choosing the lowest you will save maximum amount of diskspace possible, which unfortunately will result in lots of administrative overhead for large files (allocating all necessary clusters and filling them). For example a 200MB file will occupy roughly 400,000 clusters, which need to be allocated and filled with data in this case.

Choosing the highest you will waste a lot of diskspace, but adminstrative overhead is low and your drive will be faster and not that fragmented. For example a file of 10 Bytes will unfortunately occupy 64 KBytes, though.

In essence, you need to find out the optimum cluster size for your situation. Dealing with media files only (movies, fotos, music) it should be beneficial to choose a higher cluster size eg 32KBytes. With lots of very, very small files you might want choose a cluster size closer to 512Bytes (4 KBytes is the default cluster size formatting drive with Windows).

Nevertheless, there is a conflict between speed on the one hand and using space to the maximum extend on the other hand.

More information about NTFS here

https://www.howtogeek.com/136078/what-should-i-set-the-allocation-unit-size-to-when-formatting/

and even more here

https://en.wikipedia.org/wiki/NTFS