Ok with a second SV843 refurb, smartctl -x initially gives:
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE
5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0
9 Power_On_Hours -O--CK 100 100 000 - 0
12 Power_Cycle_Count -O--CK 099 099 000 - 4
177 Wear_Leveling_Count PO--C- 100 100 005 - 0
179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0
180 Unused_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 6214
181 Program_Fail_Cnt_Total -O--CK 100 100 000 - 0
182 Erase_Fail_Count_Total -O--CK 100 100 000 - 0
183 Runtime_Bad_Block PO--C- 100 100 010 - 0
184 End-to-End_Error PO--CK 100 100 097 - 0
187 Reported_Uncorrect -O--CK 100 100 000 - 0
190 Airflow_Temperature_Cel -O--CK 077 073 000 - 23
195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0
199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0
202 Unknown_SSD_Attribute PO--CK 100 100 010 - 0
235 Unknown_Attribute -O--C- 099 099 000 - 1
241 Total_LBAs_Written -O--CK 100 100 000 - 0
Then I ran dd if=/dev/urandom of=/dev/sdc bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB) copied, 8.45415 s, 12.4 MB/s
Then rerunning smartctl +x I get:
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE
5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0
9 Power_On_Hours -O--CK 100 100 000 - 0
12 Power_Cycle_Count -O--CK 099 099 000 - 4
177 Wear_Leveling_Count PO--C- 100 100 005 - 0
179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0
180 Unused_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 6214
181 Program_Fail_Cnt_Total -O--CK 100 100 000 - 0
182 Erase_Fail_Count_Total -O--CK 100 100 000 - 0
183 Runtime_Bad_Block PO--C- 100 100 010 - 0
184 End-to-End_Error PO--CK 100 100 097 - 0
187 Reported_Uncorrect -O--CK 100 100 000 - 0
190 Airflow_Temperature_Cel -O--CK 074 073 000 - 26
195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0
199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0
202 Unknown_SSD_Attribute PO--CK 100 100 010 - 0
235 Unknown_Attribute -O--C- 099 099 000 - 1
241 Total_LBAs_Written -O--CK 099 099 000 - 204800
Well, that seems inconclusive, since the LBA written count seems correct. If the SMART data was wiped, it'll likely take a little more work to realize it. I guess this one is a YMMV/proceed with caution situation. Note that I am running over a USB3.0 adapter (one from a Seagate Backup Plus 4TB enclosure I shucked), and apparently my /dev/urandom is slow (not that surprising).