I have noticed that copying a directory of files takes much slower in opus than it does in the native windows 10 explorer. This seems like some sort of bug to me as I doubt this would go unnoticed by the developers. I'm on version 12.29 x64 and the files I'm copying/duplicating are on a NAS that I'm connecting to via 10gig. Windows explorer does about 1gb/sec while directory opus does 50mb/sec on the same machine.
This behavior does not seem to happen with drives directly connected to the machine, so clearly there is some difference directory opus is effected by while the native windows explorer is not.
Make sure it's really taking longer, looking at the network traffic in Task Manager, as the progress dialogs in both programs may not measure speed or time in exactly the same way, and File Explorer's dialog can also close and look finished before the data has been completely sent over the network.
Beyond that, some NAS and networks may run faster (or slower) if you adjust the buffer sizes:
2 MB and either 0 or 1 MB work well for me, but it can depend heavily on your setup and the NAS at the other end.
(Note that changing copy_nonbufferio_threshold can also cause problems with some USB devices and file systems that don't properly implement non-buffered I/O. It's rarely used, so not everyone tests their devices with it.)
In the longer term, we will be providing a future option to (where possible) copy data using the same high-level API that File Explorer does, so you should then see identical speeds in both programs then without having to configure anything.
I will play with those two settings again, I have experimented with different numbers and did not see a performance difference (and yes, I did restart directory opus). The speeds are actually different, in my test case, windows explorer takes 20 seconds to copy while directory opus takes over 3 minutes.
Are you copying from and to folders on the same network drive?
I didn't think of that before, but if that's what you're doing it would the large speed difference, and the settings I mentioned won't change what happens very much.
If the server supports it, File Explorer can instruct it to do the file copy locally when the source and destination are both on the same server. Opus will currently read the data over the network and then write it back to the network. (The future change I mentioned will make Opus do the same thing File Explorer does, so that difference will go away.)
Did you ever find a solution to this? Your graphs look almost IDENTICAL to mine, except that DO regularly writes out at 100MB/s while Explore is performing at 600-900MB/s.
This is via a 40GbE fiber to TrueNAS Scale with 4x mirrored VDEVs and all the other goodies.
Yours is the closest post I've seen to my issue. Thanks! -Ian
By default, Opus 13 copies using the same API that File Explorer uses (different to Opus 12, which this thread was about).
For basic file copies (not involving archives, FTP, etc.), you should see no speed difference at all between Opus and Explorer, unless something else is interfering (e.g. antivirus).
