(copy från amazon review)
Size Name: 2TB
ok, so this drive is listed as the "Seagate ST2000DM001" and guess what; other than that it sports 2 Terabytes, it tells you nothing whatever about what drive you'll end up with, because Seagate has chosen to obscure and omit relevant Data between different builds with vastly different performance.
The short advice: Only purchase versions xxExxxxx [and possibly x24xxxxx - x24 is unverified info so far, see notes below] of the 2TB model. This uses 2 platters and 4 heads.
It performs 30% better than the version with 3 platters, which has an xxFxxxxx [or possibly x36xxxxx] designation. Avoid those!
You'll need to contact the seller and ask them to check the code on the drive. If they can't verify, don't buy it, better to get a drive from a different company, where its hopefully not a surprise game of what's in the box.
S - SU - Suzhou China
W - WU - Wuxi China
Z - TK - Korat Thailand
F = 3 platters with either 5 or 6 heads (bad 2TB drive or good 3TB drive)
E = 2 platters with 4 heads. (good 2TB drive)
D = 1 platter with 2 heads. (good 1TB drive)
Weight info received in a comment here, suggests that the 'good' 2-platter drive weighs 534 grams, while the 'bad' 3-platter drive weighs 624 grams.
Seagate used to embed the information about their drives in the model number, but now they obscured it, so they can pawn off whatever they want. Send a WxE model to Publications who test drives, and then ship the crappy WxF model to unsuspecting customers who may never realize they're not getting what they thought they were buying. This should really be illegal.