Good question. TechToolPro, Drive Genius, Checkmate, and others will all perform a "
surface scan" of an SSD which would report any new bad data blocks, but that leads to some questions…
- Is a surface scan of an SSD a reliable indicator of its health?
- Would the additional write operations in a surface scan contribute to shortening the life span of an SSD?
- What is the normal failure pattern for an SSD, block by block or cataclysmic?
While SMART tests of HDDs are almost notoriously unreliable in predicting future drive failure I ran a SMART test of the SSD and HDD portions of the fusion drive in my Mac mini to compare against one another to see how they compare in what SMART parameters each reports.
- The SSD only reports 10 parameters compared to the HDD's 21).
- Five of the SSDs parameters are also reported by the HDD
- Of the 10 parameters reported by the SSD one (Power-Off Retract Count) seems totally inappropriate to an SSD and two (Total Bad Block and Wear Leveling Count) appear to be potentially useful.
- Interestingly enough of the two HDDs on my system neither report Total Bad Blocks
My
initial conclusions are…
- In the mid to short term SSDs will almost totally supplant HDDs for all but bulk data storage.
- Given a tool like TechTool Pro 8 that reports all the SMART parameters there are individual parameters that could potentially warn a knowledgable user of impending drive failure
- Personally I have reservations about the efficacy of a surface scan of an SSD until I get answers to my questions.
- There is no definitive test or tool for checking SSD health or forecasting impending failure
- There is a market for a tool or measurement that can predict SSD failure within a reasonable degree of accuracy.
- I have been known to be wrong more than once in the past and certainly will be wrong in the future
FULL DISCLOSURE TechTool Pro is the only tool
I know of that displays all of the SMART parameters reported by the drive. I have no relationship, pecuniary or otherwise, with Micromat (the developer of TechTool Pro) other than that of a satisfied customer.
