Running an extended set of tests to fine-tune the performance of the Bvckup 2 bulk copier.
It's an inherently simple matter of determining an optimal size and count of read/write buffers used to ferry data from source to destination. There are however ... erm ...
A source can be local or it can be over-the-network. There are slow local devices (e.g. a USB2 drive) and there are fast local devices. There is a warm, there is a cold cache and there are files that are cached only partially.
The writes can go out in lots of smaller chunks, all in parallel, or with a smaller number of large buffers. Again, it can go to a local device or over the network. The app can also explicitly flush all buffers after copying or leave flushing to the system.
The above graph is the I/O throughput of a 0.5 GB file being repeatedly copied from the local HDD to Synology Diskstation over a Gigabit wire. What changes between the runs is the buffering strategy and as you may notice there
Still need to run several over-nighters to gather more statistics, but there is already a couple of things that can be changed in the copying code to make it run faster.
Scheduled to appear in the Release 72, coming up shortly.