Seagate Cheetah Date of Manufacture

Lately I found myself in the possession of several Seagate Cheetah 15K.7 SAS drives. These represent the pinnacle of hard disk engineering; with 15,000 RPM, the drives deliver up to around 200 MB/s sustained throughput (both read and write!) and have average access time approximately 5 milliseconds. They run a bit warm but are surprisingly quiet.

Naturally I’m interested in knowing when the drives were made. But only one of four drives has a clear “DOM: 08/2011” printed on the label:

Seagate Cheetah 15K.7 a Date of Manufacture on the label

The other three drives have nothing on the labels that would clearly identify a date of manufacture:

Seagate Cheetah 15K.7 with no apparent date of manufacture

That is different from most Seagate consumer drives which have a “date code” on the label.

Now, it’s possible to punch the serial number into Seagate’s warranty lookup. But that only works for drives directly sold by Seagate, and two of my drives weren’t (one of them is Dell branded, the other has no other identifiable branding). And even when the warranty lookup does work, it does not determine the actual date of manufacture. For the drive manufactured in August 2011, the five-year warranty expired in November 2016. Since the warranty period starts counting from the date of purchase, it makes sense that it only gives a ballpark estimate—basically if the warranty expired in Nov 2016, the drive was likely manufactured several months prior to Nov 2011.

These Seagate drives do not appear to report the date of manufacture through software (some other drives do), and although Seagate knows exactly what the drives are based on the serial number, the date of manufacture is not shown there either.

But there is one other piece of information on the label—the lot number—that looks like it might include the date of manufacture. Does it?

The lot numbers look like this: S-01-1207-2, S-12-1143-1, or A-01-1026-1. The four-digit sequence looks very much like it could be a year and week. But for the drive whose label clearly says it was made in August 2011, the lot number digits are 1207. Obviously 2011 is not 2012… or is it?

It is somewhat well known that Seagate consumer drives have four- or five-digit “date codes” that look like (for example) 05353. The key is that the date code is based on Seagate’s financial year, which starts in on July 1st of the preceding calendar year, as described for example here. That is, Seagate’s FY12 started on July 1st, 2011.

Now, 1207 maybe doesn’t look so far off anymore. The seventh week of FY12 would have been in Summer 2011 in fact. Maybe the lot code contains the year/week and day of the week? If we take the S-01-1207-2 and turn it into a five-digit (12072) or even four-digit (1272) Seagate style date code, and plug it into a converter, like the one here or here, we will get two slightly different results but we will get a date in August 2011.

It is worth pointing out that these drives usually also have a visible manufacturing date on the bottom PCB. It’s in the usual four digit YYWW format, but naturally it only shows when the PCB was made, not the whole drive. It can still be useful for getting an estimate. Unlike many other drives, the Cheetahs have no chips visible without taking them apart (a good thing—harder to damage by careless handling), and hence no other sources of information for guessing when the drives were made.

I scoured the Internet for legible photos of Cheetah drives with a clear date of manufacture on the label. I found one IBM-branded drive with a lot code of A-01-1005-1 and DOM: 01AUG2009. Indeed plugging 10051 as a date code into the converter here we get August 1, 2009.

Another drive was seen with lot code S-01-1645-6 and DOM: 05/2016. Again a 16456 date code is in fact May 12, 2016. Therefore I am inclined to say that yes, the lot code can be used to determine the date of manufacture of Seagate’s enterprise drives, at minimum the Cheetahs.

I could not find this lot number to date code relationship documented anywhere; it is guesswork on my part, but so far it has been confirmed by observation where both the lot number and date of manufacture are available. Perhaps this information will help someone.

Summary: For Seagate drive lot numbers in the format A-XX-YYYY-Z, YYYYZ is almost certainly a five-digit date code which can be converted into a date of manufacture.

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