Really Slow Copying Files from iMac to Seagate External HDD

Terence, yes I am talking about the Photo.app library. Are you referring to this Apple article - https://support.apple.com/en-us/HT204258 - where Apple says that Photos libraries can't be saved to NTFS drives? If so, then OK - thanks for the tip. I was trying to use my HDDs so that they can go back and forth between Windows laptops and the iMac, but I guess I'm going to have to reformat one of the two HDDs into the Mac OX Extended format (https://support.apple.com/en-us/HT201909).

Considering the size of the Photos and iTunes involved here, it looks like FAT32 is out of the question due to its restrictions on individual file size (4 GB) (www.howtogeek.com/235596/whats-the-difference-between-fat32-exfat-and-ntfs/).

Before I go about reformatting a HDD, I am open to any tips I'm overlooking for making NTFS work with the iTunes and Photos libraries. Argh! So much for interoperability! :-~

I have a USB 3.0 cable going between the iMac and the HDD to copy over iTunes (43.85 GB) and Photos (512.GB). I am using the HDDs (i.e., not other computers) for backup purposes (I hook up only one at a time, of course). The Photos transfer has taken 8 hours in the past, now the estimate for the transfer process went up to 17 days. My keyboard is connected via USB cable, but I restarted the transfer after disconnecting the keyboard - still no change.

I closed out all other programs, and I rebooted the iMac multiple times.

The HDDs are in Windows NTFS because I need to be able to use them for both Apple and Windows computers.

After I disconnected the keyboard, the transfer estimate spiked up at 10 days but went down to 5 days.

On the Activity Monitor, the Activity Monitor takes 3.6% of CPU usage. Everything else is a lower percentage with the exception of "kernel_task", which bounces between ~8.0% and ~34.0% of CPU usage (real memory size is 551.3 MB, virtual memory size is 69.16 GB). Should I try to terminate "kernel_task", or should I let it run?

THe HDD is now disconnected, and "kernel_task" hovers between 0.5 and 1.0%. What about having the HDD connected would cause "kernel_task" to jump up to the 8-34% range? I suspect this problem is causing the issues with the file transfers.

Terence - I reformated the HDD to MAC OS Extended (Jouraled), and it's so far, so good. While the estimate for the transfer of the Photos library is still 8 hours, the transfer is going well. During a quick survey of the Activity Monitor, the "kernel_task" maxed out at 5.7% of CPU usage, and the iMac is A TON more responsive going between programs while the file transfer is going on in the background. Thanks so much!!

I just Googled "kernel_task", so I take it that killing it probably isn't the answ I'm looking for ...😊

I was able to copy over the Photos library just fine in the past... I'm not sure why I'm getting the problem now.

Terence, OK - thanks. I'll reformat one of the HDDs into Mac OS Extended (Journaled) then try the transfer process again. Darn - I was hoping that I could avoid going that route. :-~