So much hours? Really?

Now you are seeing the performance difference between two SSD drives.

A Certify process writes a pattern, then reads it back. It appears one of the SSD drives is much slower than the other.

One thing I have seen in industry news that some Samsung's lose up to 50% of their performance over time. Sometimes a Certify can refresh them, but this issue seems to affect larger capacity SSD drives. What I understand is around 5,000 power on hours is generally when this happens.

Regardless, it is a point that not all devices are the same. If these are both new, then perhaps you have enough data to complain and try to get a replacement.

Yes we highly recommend the certify on new disks and SSD devices. In your specific case, you may have discovered you have a defective SSD, on day 3. Imagine discovering this after 6 months? or after the SSD failed?

Disks have a initial failure rate, then a gradual failure curve over time. Certify cuts the initial failure incidents dramatically so it is totally worth it to certify disks.

Thanks a lot for answering. Below crystaldiskinfo of both disk. Tell you who is the one that show (at this time 52hours) I don't know.

To identify an SSD is a little harder than a HDD.

If the dock/enclosure you have has LED indicators, use Blink Disk Light in SoftRAID, which will show you which disk is which.

In addition, check with SoftRAID disk tiles. Look to see both disks are communicating as USB 3 that one of the disks is not communicating as USB 2.

They are both in an Akitio Thunder2 Quad Mini enclosure... And I started certification at the same time.

At the moment I have opted for an Appleraid0. Maybe less certified but it's up and running in less than a minute.

I have TM backup running so I can bear with a failure and in less than 3 hours I'm ready again.