I tried a litte C program found at the bottom of this OSNews article on 4096 sector drives on a WD15EADS-00P8B0.
That program writes 1000 blocks of 4096 at a adress multiple of 4096 + a given offset of 512 bytes. (REQUIRES LINUX AND C KNOWLEDGE TO RUN)
My results are that changing the offset deeply impacts the performance of this drive, when it should not, since this is supposed to have good old 512 bytes per sector and it reports to have one logical sector per physical sector. On my laptop infact the performance are the same with any offset.
On the caviar green instead I ran into a few weird behaviours:
offset 0 and offset 8 are fast, any other is like 5 times slower. This makes it look like the drive uses 4096 bytes sectors.
sometimes the drive totally froze for a many seconds, just like many user are experiencing. Once it took almost 3 minutes to complete the writes instead of 3 seconds.
It seems that this drive has a partial or buggy implementation of the “advanced drive format”. I even tried to align partitions to multiples of 4096 but it did not remove the freezes (it might have helped the performance tough).
I am sick of this drive… There is something wrong here.
If there is a way to avoid those freezes I want to know it, else I want an equivalent drive or my money back.
PS: the align tool reports it as a non AF drive too.