In my experience I see something I’ll call double copy… in a least complicated setup.
Backup source D:
Temp Dir C:%temp%
First read files from D:, create dblocks in temp, move to destination
No doubt the job is done but high resources are required. In this case even with no compression and encryption high HDD I/O is needed.
For local storage like you’re using it might work better if you use
--tempdir= to point to somewhere on E: and then
--use-move-for-put to move the resulting files instead of copying them.
2 ideas from @kenkendk that may improve performance and reduce disk usage:
Multithreaded backup engine:
Processing DBLOCKS and Temp files in memory:
I split this off to it’s own “disk usage” specific topic as fixes for this and CPU usage issues aren’t likely to overlap much.