Yousuf Khan wrote:
I have a folder on one of my SSD drives that takes 8 to 10 hours to back
up. It is only about 1.4 GB, but it is allocated 2.4 GB of space
altogether, and there are 580,000 files here. Indicates that per file
it's using up a little bit over half of a cluster on average. File
system is NTFS.

Meanwhile, this same drive can backup the remainder of the drive in
under 2 hours, and the remainder of the drive is 390 GB! Is NTFS this
inefficient for small files like this?

Yousuf Khan

Have you tried to "defragment" the drive ?

Normally, the "optimize" dialog will not offer defragmentation
as an option in Windows 10. It's supposed to offer "TRIM" as
the option for an SSD.

However, there is a "Copy On Write" or COW issue with SSDs.
Under the right circumstances, there will be a slowdown.

Now, consider what you're doing. Your backup software uses VSS
to make a shadow copy. It's possible some "COW activity" is happening
during the backup.

The Optimize dialog knows about this, and the Optimize dialog
has some sort of metric it uses to decide what to do. While
most of the time, it will only offer TRIM, I bet in your
case, it's "going to have a COW" and defragment your drive.
This should not be as thorough as a regular defragment,
and the design of what's done, should have something to do
with whatever the root cause of "having a COW" is.

I've not seen this slow behavior here, so have no
first hand experiences to offer on it. Note that over the
years Windows 10 has existed, the behavior of the Optimize
panel has been "as crazy as Cocoa Puffs". The software
frequently could not properly tell an HDD from an SSD,
and it would be damn hard to see any "subtle" behaviors,
when this software has had so many bugs in the past. I've
had a machine full of HDDs offer nothing but TRIM and
the Optimize panel declared all my drives as SSD drives.
Which is total bull**** and most annoying when you
actually want the defrag to work. As far as I can remember,
Optimize is working in 1909 OK now. It's been a hell of a
bumpy ride though, over the years.

See if you're offered a defrag option.

Do Properties on the drive letter, and in the Tools tab
you'll find the Optimize. Then retest your backup rate
after the partition has been cleaned up.

Paul