当然何度もSMART(brew でsmartctl をインストール済み、ただしverdor定義が多すぎて情報が少ない)で情報を見ていますが、分かる範囲で問題ありません。使用時間も180時間程度です。ディスクユーティリティでもSMART検証済みになっています。新規インストールできる時点でこの種の問題はクリアされていますよ、SMART情報がおかしければインストールできませんから。
$ smartctl -a /dev/disk0
smartctl 6.6 2017-11-05 r4594 [Darwin 16.7.0 x86_64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Apple SD/SM/TS...E/F/G SSDs
Device Model: APPLE SSD SD0256F
Serial Number: 140699409986
LU WWN Device Id: 5 001b44 bcdeb9a42
Firmware Version: A223321
User Capacity: 251,000,193,024 bytes [251 GB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: Solid State Device
Form Factor: Unknown (0x0012)
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 6
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Feb 26 15:08:05 2018 JST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x00) Offline data collection activity
was never started.
Auto Offline Data Collection: Disabled.
Total time to complete Offline
data collection: ( 0) seconds.
Offline data collection
capabilities: (0x00) Offline data collection not supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
SMART Attributes Data Structure revision number: 40
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 100 100 000 Pre-fail Always - 0
5 Reallocated_Sector_Ct 0x000f 100 100 000 Pre-fail Always - 0
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 185
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 9293
169 Unknown_Apple_Attrib 0x0022 100 100 010 Old_age Always - 1671090408896
173 Wear_Leveling_Count 0x0022 197 197 100 Old_age Always - 25776750618
174 Host_Reads_MiB 0x0030 100 100 000 Old_age Offline - 3426909
175 Host_Writes_MiB 0x0030 100 100 000 Old_age Offline - 3878803
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 266
194 Temperature_Celsius 0x0022 073 073 000 Old_age Always - 27 (Min/Max 16/81)
197 Current_Pending_Sector 0x0032 000 000 000 Old_age Always - 0
199 UDMA_CRC_Error_Count 0x003e 100 100 000 Old_age Always - 0
244 Unknown_Attribute 0x0002 000 000 000 Old_age Always - 0
SMART Error Log not supported
SMART Self-test Log not supported
Selective Self-tests/Logging not supported