(Information from approximately 2018)



part 1:

  Type      read time     program time     erase time    erases per block
  ----      ---------     ------------     ----------    ----------------
   SLC        25 uS      200 -  300 uS     1.5 - 2 mS       100,000       Single level cell, one bit per cell
   MLC        50 uS      600 -  900 uS           3 mS         5,000       Multi ( = two)
   TLC        75 uS      900 - 1350 uS         4.5 mS         1,000       Three



part 2:

                                Random       Sequential
        Device               Read    Write  Read    Write
        ------               -------------  -------------
 Samsung 840 Pro SSD         103     287     421     384
 Seagate 600 SSD              84     252     424     374
 Intel SSD 335 SSD            39     222     344     354
 Seagate Savvio 15K.3 HDD      2       2     223     223   (disc for comparison)

                             All in MB/S



part 3:

                                          LSE = Latent Sector Error
                                          URE = Unrecoverable Read Error

     Error type   cheap     costly
                e.g. SATA  e.g. SCSI
     ---------- ---------  ---------
     LSEs          9.4%      1.4%
     Corruption    0.5%      0.05%

  (data from 1,500,000 discs over three years)



part 4:

Findings about LSEs:
  Costly drives with more than 1 LSE are just as likely to develop additional
         errors as cheaper drives.
  For most drives, annual error rate increases in year 2.
  The number of LSEs increases with disc size.
  Most discs with LSEs have less than 50.
  Discs with LSEs are more likely to develop additional LSEs.
  There is a significant amount of spatial and temporal locality.
  Disc scrubbing is useful (most LSEs were found this way)

Findings about corruption:
  Chance of corruption varies greatly across different models within the same
         drive class.
  Age effects are different across models.
  Workload and disc size have little impact on corruption.
  Most discs with corruptions only have a few.
  There is sptial locality and some temporal locality.
  There si a weak correlation with LSEs.




From "Operating Systems: Three Easy Pieces"