To force the drive's controller to test all sectors you can do a Full format (not a Quick format). If on the other hand all the sectors are tested and found to be good then the Pending Sector Count will reset to zero an no sectors will be reallocated.Ī sector cannot be tested while it is in use. Reallocated Sector Count' will go up by one. When a bad sector is replaced like this the Pending Sector Count will go down by one, and '05. Only when they have been tested and confirmed as bad will they be replaced by a sector from a spare pool unused sectors, set aside for this purpose. They are not necessarily bad sectors, but they are 'pending' a test by the drive's internal controller to confirm whether or not they are bad. It means that 17 sectors may be at fault as they have been found to be unreadable at some time in the past. The value of B hex (17 decimal) for 'C5, Current Pending Sector Count' is a potential fault, not a confirmed one. The SSD will not be usable as a normal drive, but the user should be able to retrieve storedĭata and transfer to a new device.Should I be worried? The drive has done less than 3000 hours and is already showing a caution in the health status according the CrystalDiskInfo. When Attribute 180 reaches 0, the firmware will place This number decreases as the number of retired blocks increases. This number varies based on the underlying NAND architecture, the firmware architecture, and the user capacity of the drive, 'Attribute 180: Unused Reserved Block Count (Available Spare Blocks on PCIe SSDs)Īgain, as the name implies, this is the count of extra blocks available to be used in case bad blocks need to be retired. I go to Crucial's website and of course they confused me even more:

Both are new drives and shows only 1 power cycle. When I check SMART one drive says Unused Reserved Block Count is 44 while the other drive is 37. I just got two 500 GB Crucial MX500 SSDs.

Crystaldiskinfo mx500