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Someone please help me understand S.M.A.R.T. attributes...

PostPosted: Fri Jun 10, 2016 10:49 am
by Kherr
Hey Everyone,

Can someone please give me an in-depth explanation of what S.M.A.R.T. values actually mean and how to read them? I've been browsing the Wikipedia page on S.M.A.R.T. codes and values, etc. but they do such a horrible job of trying to convey what they actually mean. I googled too, and alas, was unable to find something that describes how to read these values in depth. The Wikipedia page was great in describing the values and what they mean, but what isn't explained all that well... well... is what in the heck the 'Current', 'Worst', 'Threshold', and 'Raw Value' fields actually mean... in a sense of WHAT in the world is does the threshold matter to other values... like... for example. Here, in this screenshot:

Image

What do the values for 'Runtime Bad Block (Total)' actually mean? The Current and Worst values are the same at 100 and the Raw Value is at 0 (I'm showing the Raw Value in DEC mode), but the threshold is at 10. Since the current value has surpassed the threshold, shouldn't that category be marked as either 'fail' or 'pre-fail'? I've also read on the Wikipedia page that it goes down in count? So, the higher a value is over the threshold the better...? What? What about the Raw Value? :crazy:

In this screenshot, I'm showing on my second HDD (first physical disk) the following:

Image

What I'm seeing here are these:

1. 'Uncorrectable Sector Count' - Current value: 100, Worst Value: 253, Threshold: 0, Raw Value: 0
2. Power On hours of 11,329 while my SSD shows 10,992.
3. Power On Count of 711 while my SSD shows 734.
4. Spin-Up Time - (all values in milliseconds) Current Value: 152, Worst Value: 149, Threshold: 0, Raw Value: 11,391.

Both my SSD and this HDD were installed pre-build, so the very first time the machine was powered on both drives were present, so they should show the same counts for Power On Count and Power On Hours... right (please note that I have disabled disk spin down times, they are always on and always spinning (if mechanical))? Same question as before, what's up with the Current, Worst, Raw Value, and Threshold values for #1, and what about that Raw Value for #4? Also, wouldn't a lower current value be better than a higher current value in spin-up time ms, because faster is better? What in the heck?

Why do these values have to be so confusing? :crazy: