However, since the documentation for Disk Utility is very poor (palimpsest?), I"m not sure how khổng lồ interpret the results:
For example, the Read Error Rate is over 50 million (!), yet the Assessment is rated "Good".
So would someone mind explaining to me how to lớn interpret the results of these tests (especially the Normalized, Worst, Threshold & Value numbers)? And maybe tell me what they think of the results I got for my HDD? (Thanks)hard-drive smart Share Improve this question Follow asked Jan 6 "11 at 23:46
MartyMarty 1,85533 gold badges1717 silver badges1515 bronze badges 2 Add a bình luận |
3 Answers 3Active sầu Oldest Votes 65 You have sầu a good description of how SMART works on wikipedia. But a quick intro:
Value: This is the raw value that the controller reports. Usually it"s an easy khổng lồ understand value (lượt thích power on hours or temperature), but sometimes it isn"t (lượt thích the read error rate). Different manufacturers can use different structures & meanings for this data.
Normalized: This is the above sầu value normalized so a higher value is always better. So a 114 in read/error rates is better than 113. Again, how your hard drive converts raw data khổng lồ normalized value is vendor specific.
Worst: The worst normalized value that your drive had in the past (where 99 is likely the factory setting).
Threshold: When the normalized value is lower than this value the drive is likely to lớn fail.
So, your hard disk seem khổng lồ be ok. The value of the read error rate is not the times that your drive sầu failed, but some data struct that depends on your disk manufacturer.Share Improve sầu this answer Follow edited Nov 3 "16 at 8:42
muzzamo 22311 gold badge22 silver badges66 bronze badges answered Jan 7 "11 at 8:38
Javier RiveraJavier Rivera 33.6k99 gold badges8585 silver badges108108 bronze badges 1 Add a comment | 27 Yes, generally the raw value for read error rate is nonsense. The values you want khổng lồ keep an eye on are the reallocated sector count, pending count, và offline uncorrectable. Those are the count of bad sectors that have been, are waiting to be, or can not be corrected, và the raw values there generally make sense and are the count of sectors. Share Improve sầu this answer Follow answered Jan 7 "11 at 15:46
psusipsumê man 34.9k22 gold badges6363 silver badges100100 bronze badges 2 Add a bình luận | 11 psumê man nails it.
If you read the data sheets (white papers) say at seagate.comyou will see how HDD"s are made, tested và how they really work.There is no perfect HDD, never was, never will be, (history and fact).In the olden days, we had to enter the bad sectors in to lớn the HDD controllerfrom a các mục on paper that came in the new drive box, so the controller skips them.
Modern drives have error correction. From day 1 sectors are bad.
So they bản đồ them out, this means the drive sầu skips bad sectors.In fact they are "logically swapped out" - the bad sector is mapped lớn a new, good, spare cylinder sector (it has spare cylinders - think of cylinders as tracks). This is all transparent to the outside world - except for the SMART util.
Each manufacturer can vị as they please, so some mix the error counts to lớn zero, even though there might be 10 bad sectors as soon as the drive is manufactured.
There is a 3 times rule in the drive"s firmware - it reads a sector 3 times and if all 3 times it is bad then it may vì chưng a "recalibrate" on the fly, và read 3 more times. If the drive sầu is still not ok it will bản đồ that sector lớn one of the spare sectors. This is deep in the firmware, but happens continually in the background, all transparent lớn the user.
Point 2: all HDD have natural read errors, you can learn that at Seagate too, if you want. but they all have errors on the fly. & are read again, and usually pass the test for CRC errors. if not the DRIVE tries khổng lồ swap it out.if you run the disk cool, it will last a long time và you many never run out of spare cylinders. but do look at that as psusay đắm tells you !
I"m typing this , on an old PC , running one of the first 1gb HDD ever made. and is still good. (lặng backed up ) (no laông chồng of cooling ever...) heat is the #1 killer và power surges, I run a UPS. cheers & good day. I hope this helps. (ever seen a DatA General hard disk crash? và fill the room with vast amounts of aluminum wool, curly cues? lots of fun baông chồng then... never a dull moment....