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There is a reason why there was no performance degradation: They ran the tests on "dirty" disk both times. To clear an SSD, specials methods must be used: They
by Murkin 16y ago
There is a reason why there was no performance degradation: They ran the tests on "dirty" disk both times.
To clear an SSD, specials methods must be used: They are vendor specific but the SECURE ERASE command (ATA spec) will mostly do.
- sramov 16y agoThat is correct. They just wrote data over the whole damn disk. ATA SECURE ERASE as I believe directs the controller/firmware to bring the cells to a factory state, which takes a little time because the cells only need to be marked clean, not rewritten or anything like that. The method I use on my SSD when reinstalling: hdparm --user-master u --security-set-pass 12345 /dev/sda hdparm --user-master u --security-erase 12345 /dev/sda
- Murkin 16y agoActually each cell (each bit) is reset to an initial state. It is still blazingly fast, as the erase is: 1) Done in large chunks 2) Done in parallel (most SSDs have multiple dies) 3) Does not require data transfers out of the drive. The ERASE also resets the internal data structures (dirty/etc lists).