Though when it comes to design reliable disk drives the good engineers at Seagate do suck a bit and the way this particular model issues were mis-managed by the technical support sucks BIG, but they actually know what is inside their hard disks (I mean, they designed and manufactured them, they anyway know more - and very, very often won't tell - than anyone else on the specific topic).
The Seatools are for Seagate a "key" app, if either the short or long test fails, it will produce a code that will entitle you (if the disk drive is still under warranty) to have a replacement unit.
Though it is of course possible that because of the above the tool is maliciously tuned to make drives appear more healthy than they really are , I doubt that this is the case, as a matter of fact the common experience on this thread shows that disks that did not pass the test were anyway largely accessible and functional.
HD sentinel is a third party "generic" tool that uses the monitoring of the SMART attributes of the disk to "predict" failure.
While the approach:
is seemingly more "sound" than the "plain" check for SMART thresholds, but it is anyway a "theoretical model", seemingly nice, but only assertedly and theoretically more accurate than "plain" check.
The SMART in itself is not accurate at all, and to all practical effects it has not any relevant increase in accuracy than flippism, see:
There is not any evidence (AFAIK) that the HDsentinel method is accurate or "more accurate" than anything else, the only thing that you can say for sure of the results is that it is "more conservative", .i.e. it will start crying (sometimes crying Wolf! ) much earlier than a "plain" SMART monitoring tool, in their own words (same source as above):
According to this number, the health is disquieting. By default, this software would alert the user if the health value is as low as this number. By selecting the correct evaluation method and the correct alert levels, it is possible to predict failure long before the catastrophe. The owner of this hard disk could prevent data loss if he'd install this software before.
A low health value alone does not neccessary mean that the hard disk will surely die in the near future (to verify this, a complete (hardware) examination is required), but there is a real chance for failure. The problem of the hard disk described above can not be easily detected but as we can see, there were some signs in the S.M.A.R.T. attributes. Other hard disks with other problems may work for a long time, months or years (even if they have lower health value). Problems caused by a short period (for example, too hot environment or an incorrect power supply) will not disappear. But after fixing the reasons of such problems (using a heatsink, fan or replacing the power supply), the hard disk lifetime can be extended. Anyway, it is recommended to examine the status of these hard disks constantly or regulary and to use them as secondary data storage only. Users should make sure that their important and valuable files are stored on an other hard disk also (with a higher "health" value).
Today I installed Windows on it, then I installed SeaTools and HD sentinel.Sentinel showed 173 bad sectors.Seatools passed the short test, but not long finished properly, I'll try another long test, because my computer went to stand by.
Thank you once again for your reply!