This happens when an SSD drive performs it's own internal clean up, provisioning and trim operations. These pages may or not be continguous in the 'traditional' sense, and can CHANGE internally without any knowledge to the operating system. With SSDs the smallest block is 512 KB (a thousand times larger), made up of pages, which can be variable, but frequently 4KB. A "sector of data" on a rotational drive is 512 bytes at a physical location on the disk. It's straight forward to associate an actual physical location of a bad sector when it comes to rotational device for a memory device, it's a little more complicated. Manufacturer's can take a problem 'memory location' and move it to the over provisioning bucket of memory, or mark it to never be trimmed or garbage collected.does that mean they have to report it as a 'bad sector'. it can be open to interpretation what a 'bad sector' is. With modern SSDs and controlers using techniques likes over provisioning, trim, garbage collection, etc. For SSDs, the data has less relevance, because the standard hasn't evolved to define what that really means for SSDs, so manufacturer's have, of course, used this ambiguity to dictate the data returned to put their product in a better light. Most people I suspect pay particular attention to the 'reallocated bad sector' data for rotational drives that makes good sense. my product is good.well, actually ALL SSDs are going to report a zero for that data, or some might report '100', but so what, because it has no relevance for non-mechanical drives. For example, when a manufacturer says this SSD drive reports 'zero' whatever, i.e.
#Free utility apps mac 2017 full
So, in the case of Samsung, if the drive was rated for 2 million erases cycles, does that mean the drive has 50% of life remaining on a Crucial drive, if you never get close to using the full capacity, 50% reserved space isn't really a factor and what actually can be inferred from that as far as 'Life Remaining'. Using different criteria, Samsung drives might report back a million erase cycles remaining, but Crucial drives might use that field to report back that 50% reserved space is left. Remember, this is data reported back by the drive based on the manufacturer's interpretation. A perfect example is data field 231, loosely defined as 'Life Left' for SSD drive. Or worse, they will come up with a way to report back a lower value and use that in a positive spin, even the meaning of what that data really indicates has been redefined by them. Some makers have added on additional data fields to report so called 'SSD' specific info, but other makers are not required to use them, or if they do, don't necessarily report back the same data, since the definition is so open. When it comes to SSD/non mechanical drives, many of the data types/info defined by SMART are ambiguous at best, or meaningless, or at worse used by manufacturers to bolster their product when in fact they are irrelevant. Your strategy should be to always have multiple backups of key data, so that when and if a drive fails, your data is safe, rather than obsessing about whether to replace a drive the first time it shows any negative indication.Ģ) Regards SSDs, the SMART standard and specification was developed at a time when all drives were rotational.
Don't get caught up too much in what SMART data is saying, unless you see a trend overtime. I've had rotational drives during the initial 'burn in' period that show a increase in some of the so called negative indicators (bad sectors reallocated) but then 'settle down' and continue working fine for years afterwards with no increases. There are several industry studies which have shown that correlation between SMART data, predictions made based on the data and actual failure rates, is NOT that strong.possibly only correlated in less than a third of hard drive failures. these ratings need to be taken in context, or at least take with grain of salt.
Once data is returned, then SOME programs that try to calculate and give a 'probability' of failure or life expectancy rating. There really isn't any enforcement to keep manufacturers in line as far as how their devices report. Ultimately, the manufacturer of the drive decides how and what to report back. In many cases, manufacturers themselves don't adhere to the same interpretation of what a particular data field means relative to their product. Users need to realize, this app (and similar ones) are dependent and/or influenced by several external factors.ġ) The information returned by SMART is open to interpretation.
0 kommentar(er)
