Separate Write and then Read Test vs WRITE + read test combine

How, what, where and why - when using the software.
Commoner
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Joined: 2023.03.08. 22:46

Separate Write and then Read Test vs WRITE + read test combine

Post by Commoner »

Is seperate running of Surface Write and then Read Test after is good enough as WRITE + read test combine, and maybe Reinitialized disk surface test too for a new HDD? I don't wanna run a too much time test because I am afraid that if a run it longtime that it takes a day or two and end up power disruption that may kill the drive instead. Thank you.
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hdsentinel
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Re: Separate Write and then Read Test vs WRITE + read test combine

Post by hdsentinel »

If the drive has no real problem (eg. if it is a new drive) and its Health % is high enough, no signs of data corruption (eg. no communication problems reported in the text description of the Overview page like this https://www.hdsentinel.com/hard_disk_case_communication_error.php ) then yes, it is absolutely perfect to run the Write test - and then later a Read test.

If you launch these independently, then (as should) these tests verify if all sectors can be written - and then read.


If you use the combined Write + Read test, it also performs an additional verification to ensure that we REALLY read back what we wrote in the first step, to confirm that the data is not damaged, altered in any ways. This may be important only if the drive may reported the above mentioned communication errors so we suspect that something (usually the SATA cable but can be an external USB adapter/dock/enclosoure/USB cable in case of external drive) can cause that the data may be corrupted.

Because of this verification step the Write + Read test can help (for example) to reveal possible "fake" pendrives / memory cards: they usually show very high capacity but can't be really used for storage. The details and the the technical background explained at https://www.hdsentinel.com/how_to_detect_fake_pendrive_memory_card.php
may give thoughts about how this Write + Read works (for all kind of storage, hard disks, SSDs, pendrives, memory cards etc.)
wwcanoer
Posts: 15
Joined: 2020.02.19. 16:55

Re: Separate Write and then Read Test vs WRITE + read test combine

Post by wwcanoer »

Interesting. I started running separate sequential write (random data) and then read tests because I wanted to see the separate write and read graphs for my new nvme drives to see their behavior but didn't realize that's not as robust as the combined test. (Not really critical for a new drive with no known problems but good to recognize the difference.)
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