[..]
It is odd that it is showing an attribute 177 value of 12, but the LBAs written (attribute 241) 497447 x 512B indicate about 255MB of host writes.
So the question is what is attribute 177 counting? I did a full drive sequential write (QD1, 128KiB block size) and attribute 177 increased by 1 while attribute 241 increased by 500118016 x 512B = 256.06GB. So it seems attribute 177 is probably counting average number of erase cycles for the flash (+/- 0.5), and attribute 241 is indeed counting host writes in 512B increments.
So, it looks like Samsung may have done about 255MB of host writes as a burn-in test. But I don't understand the 12 x 256 GB = 3TB of block erases that attribute 177 seems to indicate. No way is the write amplification 12,000. My best guess is that Samsung has a special way to do a lot (about 12) of block erases to the flash without actually writing to the LBAs, and that Samsung does this as a burn-in test and/or to determine the faulty flash cells so that they can be marked bad. Or maybe the flash chips are tested separately before being soldered to the circuit board, and they all get erased 12 times, so Samsung just initializes attribute 177 to 12 on all the SSDs.
I tried a secure erase but attribute 177 did not increment, so that cannot explain it.
My drive had an attribute 177 value of 24 within the first 1-2 hours!!!
Having written only about 128 GByte to it D:
S.M.A.R.T. attributes now are at:
Code:
smartctl 6.1 2013-01-02 r3742 [x86_64-linux-3.4.11-2.16-desktop] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, [URL="http://www.smartmontools.org"]www.smartmontools.org[/URL]
=== START OF INFORMATION SECTION ===
Model Family: Samsung based SSDs
Device Model: Samsung SSD 840 PRO Series
Serial Number: S12PNEACB15543Y
LU WWN Device Id: 5 002538 55003fd17
Firmware Version: DXM04B0Q
User Capacity: 128.035.676.160 bytes [128 GB]
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
9 Power_On_Hours 0x0032 099 099 000 Old_age Always - 21
12 Power_Cycle_Count 0x0032 099 099 000 Old_age Always - 16
177 Wear_Leveling_Count 0x0013 099 099 000 Pre-fail Always - 24
179 Used_Rsvd_Blk_Cnt_Tot 0x0013 100 100 010 Pre-fail Always - 0
181 Program_Fail_Cnt_Total 0x0032 100 100 010 Old_age Always - 0
182 Erase_Fail_Count_Total 0x0032 100 100 010 Old_age Always - 0
183 Runtime_Bad_Block 0x0013 100 100 010 Pre-fail Always - 0
187 Uncorrectable_Error_Cnt 0x0032 100 100 000 Old_age Always - 0
190 Airflow_Temperature_Cel 0x0032 076 072 000 Old_age Always - 24
195 ECC_Rate 0x001a 200 200 000 Old_age Always - 0
199 CRC_Error_Count 0x003e 100 100 000 Old_age Always - 0
235 POR_Recovery_Count 0x0012 099 099 000 Old_age Always - 1
241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 292183437