psusi nails it.
if you read the data sheets (white papers) say at SeaGate.com?
you will see how HDD's are made, tested and how to really work.
there is no perfect HDD, never was, never will be, (history and fact)
in the olden days, (me) we had to enter the bad sectors in to the HDD controller
from the comes with paper, in the new drive box, so the controller skips them.
fast forward, modern drives (not drivers) , or Winchesters as we once called them
have error correction, from DAy1, EVEN DAY 1 , SECTORS are bad.! (fact)
so they , map them out, this means the drive does the skipping of bad sectors
in fact they are logically swapped out, in that the bad sector is actually MAPPED
to a new , good, spare cylinder sector ( it has spare cylinders)
(think of cylinders as tracks) (all transparent, to the outside world,cepting , s.m.a.r.t util)
Each manufacture, can do as they please, it's their design, so some set the error counts to zero day1 even though there are 10 bad sectors day1. see?
other set it to zero. after all , it's none of your beeswax. (see I'm a perfect drive , i lie to you) (but does not matter, day1, in the least)
Also there a 3 times rule deep in drives. it read it 3 times and if all 3 times its bad
it may do a "recalibrate" on the fly, and read 3 more times. if ok now, then ok.
if not it will spare that sector. (this is deep in the firmware, but tells you whats going one every second you use it , all transparent to the user)
Now how does x MFG report raw errors, at each 3 reads wrong, or after the calibrate?
it's up to company X, so like he says above, it's not important unless you have many drives of the same kind and you see some odd trends........???????
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. and are read again, and usually pass the test for CRC errors. if not the DRIVE tries to swap it out.
if you run the disk cool, it will last a long time and you many never run out of spare cylinders. but do look at that as psusi tells you !
I'm typing this , on an old PC , running one of the first 1gb HDD ever made. and is still good. (im backed up ) (no lack of cooling ever...) heat is the #1 killer and power surges, I run a UPS. cheers and good day. I hope this helps.
(ever seen a DatA General hard disk crash? and fill the room with vast amounts of aluminum wool, curly cues? lots of fun back then... never a dull moment....
watch the swaps. and be happy.