[Tomset]

Вот так это считается у сигейта

Seek Error Rate

The raw value of each SMART attribute occupies 48 bits. Seagate's Seek Error Rate attribute consists of two parts -- a 16-bit count of seek errors in the uppermost 4 nibbles, and a 32-bit count of seeks in the lowermost 8 nibbles. In order to see these data, we will need a SMART utility that reports all 48 bits, preferably in hexadecimal. Two such utilities are HD Sentinel and HDDScan.

I believe the relationship between the raw and normalised values of the SER attribute is given by ...

normalised SER = -10 log (lifetime seek errors / lifetime seeks)

In the above formula, if the drive has recorded no errors, then we would still need to set the number of errors to 1, otherwise the result would be indeterminate.

The following table correlates the normalised SER against the actual error rate:
90 = <= 1 error per 1000 million seeks
80 = <= 1 error per 100 million
70 = <= 1 error per 10 million
60 = <= 1 error per million
50 = 10 errors per million
40 = 100 errors per million
30 = 1000 errors per million
20 = 10 errors per thousand

A drive that has not yet recorded 1 million seeks will show 100 and 253 for the Current and Worst values. I believe this is because the data are not considered to be statistically significant until the drive has recorded 1 million seeks. When this target is reached, the values drop to 60 and 60, assuming there have been no errors.

By way of example, here are the SMART data for my 13GB Seagate HDD:
http://www.users.on.net/~fzabkar/SmartUDM/13GB.RPT
Attribute ID Threshold Value Worst Raw
===============================================================
Seek Error Rate 7 30 53 38 052E0E3000EC

The number of lifetime seek errors = 0x052E (uppermost 4 nibbles) = 1326

The number of lifetime seeks = 0x0E3000EC (lowermost 8 nibbles) = 238 026 988