I frequently need to transfer files between 10 GB and 1 TB as part of my work, typically between external drives and network servers. Whenever I transfer files, the computer slows down to being completely unusable. E.g. it can take five minutes to open a terminal window or browser, even if the application is already running.
Because of an "air gap" situation (isolated network) I have two Mac Minis, one with 16 GB RAM and one with 8 GB(not upgradable). The 16GB machine doesn't slow down much while transferring. The 8 GB mini is pretty slow in general, but works fine for mail, browsing. This one slows to a crawl, so in practice I can only start transfers when leaving the office. The transfer speed itself remains pretty OK -- typically 20MB/s limited by the remote server. I use FileZilla, scp or rsync, the computer slows down all the same.
I use different external drives, but it is also slow to transfer to/from the internal drive.
Is there any parameter I could adjust, and are others seeing this?
System / transfer parameters
- Computer model: Mac Mini Late 2014 / 2.6 GHz / 8 GB 1600 DDR3
- Operating system: macOS Mojave v. 10.14.3
- Internal disk: 1 TB SATA 5400 RPM APPLE HDD HTS541010A9E662 formatted as Encrypted APFS
- External disk 2 TB SATA formatted as Encrypted Case-Sensitive Journaled HFS+
- Alternative external disk: 2 TB exFAT formatted (not encrypted)
- Network protocol: SSH-based protocols (scp, sftp). Other protocols also seem to be affected, including HTTP download via the browser.
After uploading for 15 minutes the computer is very slow. Memory status again:
But it seems to have improved a bit in comparison to how it was before. I'm able to edit this question and take screenshots etc. with only a little bit of patience. I believe it gets worse after a while though.