Is this normal and will you accept it?

[Commoner]

Hello. May I ask if is it normal for a brand new Hard Disk Drive to have a very dark green and slow blocks in Surface Test Reinitialized Disk? Will it goes bad and became a bad sector faster than those lighter block ones if I put some files on it if I choose to accept and use the disk? Or can I ask for them to return and replace it, you think will they replace it? The disk WD40EZAZ-00SF3B0 and these are the results of the test.

20230309-020938_RI_WDC_WD40EZAZ-00SF3B0.jpg (1.04 MiB) Viewed 2096 times

IMG_20230309_021718_1.jpg (1.57 MiB) Viewed 2096 times

Thank you.

[hdsentinel]

Yes, I can confirm that this is possible and can be normal with this (SMR) hard disk type.

Generally SMR drives may show such behaviour: during the Reinitialise Disk Surface test, they may show

- darker green blocks at the end of the disk surface area
- darker green blocks at random locations or sometimes in a repeating pattern

This does not mean problem with the hard disk itself or the software/test, just it means that the disk drive processes write commands slightly differently than traditional CMR drives.

If you check:
https://www.hdsentinel.com/forum/viewtopic.php?p=20809
this forum topic shows similar with different type of WD hard disk.

The important is that the Health should be 100% (no problems reported) and if I'm correct, a Disk menu -> Surface test -> Read test should show no darker green blocks (and especially should be no yellow or red blocks).

[Commoner]

Yes thank you, your right, I already run Read Surface Test and Write Surface Test separately and was not found any dark green blocks. When you said "Generally SMR drives may show such behaviour: during the Reinitialise Disk Surface test". Its just strange to me because I have 3 SMR drives before and it does not show dark green blocks when running Reinitialise Disk Surface test. But it was all Seagate Barracuda: 1TB and 2TB and this is 4TB so the test run a bit longer and got tired at the end so the speed drop down hard? But I remembered I bought used 1TB 2.5 Western Digital Hard Drive before and also show dark green blocks too when I run Reinitialise Disk Surface test. So I just thinked maybe it is not really about SMR or CMR, what do you think?

[hdsentinel]

This is why I wrote "may"
This depends on lots of factors: how the manufacturer implemented updating the SMR zones in the drive firmware, drive internals / capacity, connection (eg. USB adapter / dock may also cause) and so.

Generally this is more common with SMR drives but darker green blocks can happen with CMR drives too.

Maybe interesting but usually there is no warranty for performance: generally it is possible (and allowed by the manufacturers) that some specific areas of a drive performs slightly slower than expected. Only enterprise class drives may have warranty for performance.