I just upgraded this afternoon from Mac OS Monterrey to Sonoma. (Apple M1 Max, 64GB).
Immediately all my copies to exFAT drives have become incredibly slow. A 2.5G copy that would have taken a few minutes before takes over an hour now!
Nothing else has changed.
This is basically unusable and I'm thinking of reverting (I have a backup from before I did this). Surely there must be a workaround?
Thanks for your reply. I more fully understand your circumstances now, and of course not, you wouldn't want to change your work flow at this point.
I must also ask, are you running any sort of third-party anti-virus, cleaning, optimizing or VPN software on this Mac? Apps of this nature are not recommended to be installed on the Mac and often found to be the culprit when a Mac is misbehaving. If you do have app like this, you might consider uninstalling them and reevaluating the situation for a time.
Please reference: Effective defenses against malware and ot… - Apple Community
Immediately after an OS upgrade, macOS may initiate a new round of drive indexing by the Spotlight app which can take a toll and slow things down for a while - usually not more than a few hours.
Rebuild the Spotlight index on your Mac - Apple Support
Maybe there is something else going on with the new OS?
You might try restarting the Mac in Safe mode and see if that has any effect on the issue.
If a simple reboot of your Mac doesn’t fix things, see if the problem still happens in Safe mode. It can take a bit longer to safe boot so be patient.
How to use safe mode on your Mac - Apple Support
Safe mode will often correct weird software behavior by forcing the OS to do disk repair, clear caches and other housekeeping and disables acceleration and third-party mods. When you're in safe boot, the machine won’t be at its best performance, especially with graphics, but that's expected.
Does the problem persist while in Safe mode?
Exit safe mode by restarting your Mac normally and evaluate the issue again.
Not meaning to be disrespectful at all here, but maybe you should reconsider your use of exFAT formatting.
It's an old, admittedly established, format that has perhaps been unable to keep up with the technological advances being made in computer storage.
There's a reason Apple have developed and moved to the APFS format for use with SSDs in particular. The writing is on the wall.
As a Mac user almost exclusively, I have no need of any drive format these days but APFS. If I must, I can still rely on HFS+ for older Macs, and occasionally I might still provide a FAT or exFAT drives for compatibility with folks on that other platform.
Maybe NTFS is workable for you? It can be done on the Mac with an NTFS utility installed.
I am using a television that only accepts exFAT format for external drives, like thumb drives. It isn't even that old.
Also, I frequently write disks that need to be read by non-Mac systems. APFS is not such a system.
Up until a few hours ago I had a perfectly reasonable workflow using completely standard and boring technologies that all modern computers understand. Then I upgraded and it's broken. I do not believe this is a fault with me or what I am doing.
Perhaps I think differently as an engineer, but if I use a very widely used file system that has been a standard for almost twenty years and is usable over a wide variety of computers, I expect it continue to work.
I'm sorry - I tried to write the above as politely as possible, but "give up on exFAT entirely"?
I find other examples of people with the same issue online.
Interestingly, `cp` at the command line seems to work at the normal speed.
While it's copying, `ls -cail` gives very weird results unlike any I have seen:
18446744073709551586 -rwx------ 1 tom staff 1611661312 Feb 20 22:21
In fact, these results persist when the copy is finished, even though the file appears to work fine. (Note that the claimed size is in fact greater than all the memory in the entire world.)
This seems dramatically broken. Replacing all my other hardware and dumping my clients who aren't exclusively Apple-based isn't a viable solution for me.
Upgraded to Sonoma, exFAT drives run an order of magnitude slower.