16" MBP extremely slow / stopping file transfer to external drive

[eccotom]

Hi everyone!
I'm a week into using my new 16" mbp, but I've noticed an issue when transferring files to an external spinning drive via a USBc to USB3 cable. The transfer will start ok, then will sometimes slow down to an EXTREMELY slow speed. Like, a transfer of a few GB that would normally take a few mins (or something like that) takes 3 hours. Other times it will stop all together, and I'll have to cancel the transfer. Here are things I've tried:
- multiple drives (it isn't one fault drive - I've had it happen on 3 separate drives now)
- multiple cables: I've tried 4 different cables
- multiple ports on the machine: I've tried all of them, same thing
- I've rebooted various times.
it seems to be an issue in the machine itself. I have no idea if it's hardware or system related.
Has anyone experienced anything like this? Any ideas?
Thanks!

 

[Fishrrman]

How MANY files are you transferring?
How LARGE are the files?

Could one or more of them be corrupted?
A corrupted file will abort a file copy by the finder.
All it takes is one "bad one" in a thousand, the ENTIRE transfer will fail. And it won't even tell you why.

Can you copy the files in "smaller chunks"?
If you copy a few files to a USB flash drive, does that transfer go ok?

What format is the drive to which you are copying?

 

[eccotom]

hey, thanks for the reply

I've tried single large files, and multiple smaller files. Sometimes its fast, sometimes slow. it varies
sometimes it starts slow and stays, other times it starts fast then goes slow.

I've tried many many different files.

even with a few files it slows down sometimes. sometimes it doesn't.

the drive is OSx journaled .

random hey!

 

[bsbeamer]

Install DriveDx and run a check on the drive to make sure it’s not failing. Also can test with AJA System Test Lite or Blackmagic Disk Test with drive as a target for speed. Some spinning HDDs get less than 90MB/s write speed, so may just be the drive speed at play.