I recently got a 4TB SSD and transferred my data from my 3TB external hard drive. Both of them were formatted as NTFS 4096 bytes. After the transfer, I found some files on 4TB SSD were bigger than the external hdd. Totally, around 500 MB is different. So, I'm wondering if it can happen and why.

 

Sounds funny. Did you format the external disk yourself or were it preformatted? Or did you use a special tool for transferring the files or just explorer?
The difference sounds so typical for a difference in cluster size (file size vs. size on disk).

 

Last edited: Dec 7, 2019

It was preformatted (I forgot what it was) and I re-formatted with Disk manager at first (ExFat) and re-formatted with explorer (NTFS 4096 bytes) eventually. When I formatted with exFat, it ate too much space, so it couldn't copy all the files from the original drive. Thus, I re-formatted with NTFS.
Here is the screenshot of my drives' status.
Forget about the last one. The first one (left side) is my original external hard drive (WD Ultra HDD 3TB), and the second one (right side) is the new one (WD Blue SSD 4TB) which has the issue.

 

I didn't realize TRIM function caused the issue. New technology...
Plus, didn't realize defragging helps to save the space of ssd.
Thx!

 

And also shortens the lifespan of your ssd too. In some cases where an SSD is old and has undergone many re-writes, it can even brick the ssd entirely, rendering it useless. By default SSD controllers optimize performance by moving blocks of data automatically using the TRIM function, no need to defrag.
All ssd companion software i am aware of, includes a manual optimization function that you can use, if in any doubt. Defragment shouldn't be used as it actually performs a whole re-write on whatever your entire SSD's capacity is.
With that said, a Samsung 860 EVO is rated at a 1200TB write endurance, so if you have an SSD with an equivalent or better endurance and feel adventurous, go ahead and experiment.
Cheers

 

Last edited: Dec 8, 2019

For Win 8/10 defrag on drives marked as SSDs by the OS, only initiates a TRIM command. Therefore defrag is enabled even for SSD by default. And by default defrag triggers a TRIM once a week.
@Niruvana uses Win 10.

So calm down, no real defrag takes place.

Was a little hard to find, but here's a reference:
https://www.majorgeeks.com/content/page/everything_you_need_to_know_about_ssd_trim.html

So the tip to disable defrag on SSDs is a bit outdated now. I don't know if there is another app/service/cronjob in windows 10 that triggers TRIM but I tested an older system (on wich I've disabled defrag for the system for a reported 609 days) a minute ago. After triggering defrag and rebooting, SSD reports 2 GB more free space (256GB SSD). So I don't think there is another trigger for TRIM in the OS. Hence disabling defrag on WIN8/10 for SSDs may be counterproductive

 

Last edited: Dec 9, 2019

Yep you 're right, i got spooked when you said defrag hehehe No worries though, cheers mate.

 

The difference sounds so t filezilla uc browser rufus ypical for a difference in cluster size (file size vs. size on disk).

 

Last edited: Dec 27, 2019