FreeFileSync Forum

both are 100% loaded

Loaded as in there is virtually no free space left on the drives?

Do you have 'Fail-safe file copy' enabled?
If so, you would need 2x the file size of free space. therube, 05 Apr 2023, 16:35

It meas hard disk activity time reaches 100%

It may also be related to the write strategy of FFS to the target disk. Using FFS to synchronize two files, both are 100% loaded, but the writing speed is different.

Here is a screenshot of my task manager (Forgive my task manager is Chinese, But you should also be able to see 100% load and 11M/50M ...

It should be mentioned that this will only happen when copying to different disks, and it will not happen when copying to the same disk.

Both are mechanical hard drives.

in conclusion:
Some files will be more than 5 times slower when using FFS synchronization across disks.

And I tried disable ...

Both https://fastcopy.jp/ and Explorer doesn't have this problem.

This is Fastcopy screenshot

No, it's not about fragmentation.

I found something very strange

The same source folder and destination folder, but the synced files are different, the speed difference is huge

微信截图_20230403212137.png

微信截图_20230403212110.png

Their file types are also the same (mp4), renaming does not affect the results, but the file copy ...

Now I am using version 12.1, and I feel that the synchronization speed of recent versions is much slower than simply copying and pasting files

this is FreeFileSync screenshot (5MB/s):

微信截图_20230402171728.png

this is windows explorer copy progress screenshot (39MB/s):

微信截图_20230402171758.png ...