SSDs and RAID

[LnxBil]

Yes, but DWPW is an hypothetical value.
Intel DC3710 1.2TB is rated at 24.3PB. By assuming a 520MB/s for writes (that you'll never reach), 24.3PB means:
24.3PB/520MB = 46730769.2 seconds = 540 days

Do you think the vendor tests each SSD for at least 540 days by writing at 520MB/s ? (this would never happen, it's impossible that you'll stay at maximum sequential write speed for 540 days, thus the test time would be much longer)

It's an hypothetical value, and calculations based on hypothetical values only provide hypothetical results.

And I can give you empirical values for the last 3 years in which no disk with a reasonable wearout factor died on me. Yet to give "some" advice, monitor your disks and swap them if you'll have a wearout difference of approx. 10%.

This is from a SAMSUNG MZ7WD960:

root@proxmox4 /tmp > ./samsung_ssd_get_lifetime_writes.bash
------------------------------
SSD Status:   /dev/sda
------------------------------
On time:      18,651 hr
------------------------------
Data written:
           MB: 12,388,357.864
           GB: 12,098.005
           TB: 11.814
------------------------------
Mean write rate:
        MB/hr: 664.219
------------------------------
Drive health: 99 %
------------------------------

More than 2 years and 12 TB written and still 99% health (Output from this smart-formatter: http://www.jdgleaver.co.uk/blog/2014/05/23/samsung_ssds_reading_total_bytes_written_under_linux.html)

 

[Alessandro 123]

How can you get a wearout difference of 10% in two SSDs on the same RAID-1 ? The writes are the same on both disks.

 

[LnxBil]

How can you get a wearout difference of 10% in two SSDs on the same RAID-1 ? The writes are the same on both disks.

Obviously swap disks from different arrays with different wearout levels, otherwise it does not make a lot of sense.