Question Copying from SSD to SSD takes longer than HDD ?

hr1975

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Does it normally take longer, much longer, to copy from an external SSD to another external SSD than from an external SSD to an external portable HD? And slower than from an external portable HD to an external SSD? And slower than from an external portable HD to another external portable HD?

13 hours ago I started a copy of 1.5tb from a 2019 Sandisk 2tb SSD (520mb/s model) NTFS to a 2022 Sandisk 2tb SSD (520mb/s model) exFAT. So far it has copied 168gb. It is still running smoothly with no errors during the copy.

Not long ago I copied 1.1tb from an external HDD NTFS to a Toshiba 1.5tb portable HD exFAT and it took about 15-16 hours. After 13 hours it was almost finished with around 900gb copied.

Over the years I have several times copied huge amounts of 1tb+ from an external portable HD to another external portable HD and it also usually takes 12-16 hours.

I use Syncback to do the copy with verify as I have done for the last 15 years. It is a backup program that I have used for years. The advantage it has over a copy program is that if there are any errors along the way such as the drive disconnecting, power going off, computer hanging, etc. you can run Syncback again and it will not try to recopy files that have already been copied. It will automatically determine what has not been copied and only copy what still needs to be done.

By the way, a week or so ago I bought a 2022 Sandisk 2tb SSD (520mb/s model), but I exchanged it for a new one because it also took so long to do the copy so I thought something was wrong with it. But this new one behaves the same so I suppose both the source and destination SSDs are behaving normally. But why is it slower to do the huge copy than when one is an external HD? I tried 2 Win10 PCs (which I have used to do these big copies many time), but both copy slow in this SSD -> SSD case.
 

punkncat

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External drives are going to be far slower than internal and also vary widely based on many factors. The USB revision or "Thunderbolt" ect. have various speed rates and then coupled with the drive type, its cache, the system doing the moving, and so forth.

To be fair, your post is a bit hard to follow with a lot of information and no specific question.
 

hr1975

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Thank you for your reply. When I wrote this in the first paragraph it seemed to me to be specific questions:

Does it normally take longer, much longer, to copy from an external SSD to another external SSD than from an external SSD to an external portable HD? And slower than from an external portable HD to an external SSD? And slower than from an external portable HD to another external portable HD?

And then at the end I wrote this question also:

But why is it slower to do the huge copy than when one is an external HD?

Detailed, precise info is normally useful for people to understand and possibly diagnose a problem or answer questions. Post that are vague and lacking details or specifics usually are pretty useless. If you are inclined to reread my post you will discover that it is not hard to follow, I think.

You will note that there is nothing in my post about internal vs. external drives. It was made clear that all drives are external.
 

USAFRet

Titan
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Does it normally take longer, much longer, to copy from an external SSD to another external SSD than from an external SSD to an external portable HD? And slower than from an external portable HD to an external SSD? And slower than from an external portable HD to another external portable HD?
Unknown, not enough info.

What level USB? 2.0, 3.0, 3.1...
What is the file composition? 1 large file is 'faster' than 10,000 small files of the same cumulative size.

Again...the external connection thing is probably more of an impact than SSD vs HDD.
 
Does it normally take longer, much longer, to copy from an external SSD to another external SSD than from an external SSD to an external portable HD? And slower than from an external portable HD to an external SSD? And slower than from an external portable HD to another external portable HD?

13 hours ago I started a copy of 1.5tb from a 2019 Sandisk 2tb SSD (520mb/s model) NTFS to a 2022 Sandisk 2tb SSD (520mb/s model) exFAT. So far it has copied 168gb. It is still running smoothly with no errors during the copy.

Not long ago I copied 1.1tb from an external HD NTFS to a Toshiba 1.5tb portable HD exFAT and it took about 15-16 hours. After 13 hours it was almost finished with around 900gb copied.

Over the years I have several times copied huge amounts of 1tb+ from an external portable HD to another external portable HD and it also usually takes 12-16 hours.

I use Syncback to do the copy with verify as I have done for the last 15 years. It is a backup program that I have used for years. The advantage it has over a copy program is that if there are any errors along the way such as the drive disconnecting, power going off, computer hanging, etc. you can run Syncback again and it will not try to recopy files that have already been copied. It will automatically determine what has not been copied and only copy what still needs to be done.

By the way, a week or so ago I bought a 2022 Sandisk 2tb SSD (520mb/s model), but I exchanged it for a new one because it also took so long to do the copy so I thought something was wrong with it. But this new one behaves the same so I suppose both the source and destination SSDs are behaving normally. But why is it slower to do the huge copy than when one is an external HD? I tried 2 Win10 PCs (which I have used to do these big copies many time), but both copy slow in this SSD -> SSD case.
Try running a benchmark on these ext ssd's see if anything shows.

You might be hitting thermal throttling when try to write huge amounts of data.
 

hr1975

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Try it without the SyncBack and Verify.

Just a regular copy/paste within File Explorer.

I have such a huge amount of data to copy and I know from experience (see my original post) that using copy/paste can cause big problems. It has happened to me. Therefore I started using Syncback (FreeFileSync also works) to do these huge data transfers along with verify. Yes, this is slower (more reliable and safer though), but the issue is why is it so much slower in this SSD -> SSD case than the SSD -> HD, HD -> SSD, and HD -> HD cases when doing the same thing on the same computers?
 

hr1975

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I stopped Syncback after 397gb had copied. Then in the Device Manager I selected Properties | Policies | Removal policy and changed it to Better performance -- Quick removal was on by default. Then I rebooted to make it go into effect.

I then restarted Syncback and it is continuing where it left off. We shall see if it speeds things up.
 

hr1975

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I have screenshots of the results of CrystalDiskMark run on the external source SSD and external destination SSD that I am currently using. I also have the Toshiba 1.5tb external HD results (HD I used not long ago to copy to). Unfortunately, when I click on the Insert image icon here it will not allow me to upload the screenshots. It only allows a URL. :(
 

USAFRet

Titan
Moderator
I have screenshots of the results of CrystalDiskMark run on the external source SSD and external destination SSD that I am currently using. I also have the Toshiba 1.5tb external HD results (HD I used not long ago to copy to). Unfortunately, when I click on the Insert image icon here it will not allow me to upload the screenshots. It only allows a URL. :(
Right.
You need to upload your pic somewhere.
Most people here use imgur.com.

Upload there, post the link here.
 

hr1975

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I stopped Syncback after 397gb had copied. Then in the Device Manager I selected Properties | Policies | Removal policy and changed it to Better performance -- Quick removal was on by default. Then I rebooted to make it go into effect.

I then restarted Syncback and it is continuing where it left off. We shall see if it speeds things up.

On further thought, I am wondering if this will help much. In normal use, of course, it would, but in this case just doing a bulk copy to an empty SSD it may not make much difference. We shall see.

In addition, it may make the Syncback verify essentially be worthless because when it reads back the destination data it may all or mostly be read from the cache. Thoughts? Of course, that would make verify faster, but then one would lose the whole point of doing it.
 

hr1975

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It finally finished about 4.5 hours ago:
  1. 397gb copied in the first 16.5 hours
  2. Changed the destination SSD policy to best performance (not the default) in the Device Manager.
  3. 1100gb copied in the next 5.5 hours.
  4. Total copied was 1.53tb.
I still do not have the answer as to why it was so much slower in this SSD -> SSD case than the SSD -> HD, HD -> SSD, and HD -> HD cases when doing the same thing on the same computers with the same settings. I did not go into the Device Manager and change the defaults in any of those cases. I am glad that there was a huge speedup though after I changed the drive policy.

I still don't know whether the verify was really working or if it was just reading from cache though, which would essentially make it useless and not doing the verification that I wanted. Years ago I had a case where a few files were corrupted in a big copy of tens of thousands of files (not using verify) and I didn't discover it until more than a year later and by that time the source drive was no longer working.

I don't know how much of the speed up was directly because I changed the Device Manager setting or if a lot of the speed up was because the verify was super quick and not doing anything.
 
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