WD 差了一大截，所以現在消費級的硬碟會選 Seagate 或是 HGST？
灰色部份是一月的數據，其他顏色是九月的數據。文中有考慮是否要換成企業級的硬碟 (enterprise drives)，但兩個評估的答案是否定的。
第一個評估是成本考量，就算一般硬碟以三年保固期有 15% 的 failure rate，相較於企業級 0% failure rate 計算 (於是直接算成 10 年)，成本是不划算的：
Today on Amazon, a Seagate 3 TB “enterprise” drive costs $235 versus a Seagate 3 TB “desktop” drive costs $102. Most of the drives we get have a 3-year warranty, making failures a non-issue from a cost perspective for that period. However, even if there were no warranty, a 15% annual failure rate on the consumer “desktop” drive and a 0% failure rate on the “enterprise” drive, the breakeven would be 10 years, which is longer than we expect to even run the drives for.
The assumption that “enterprise” drives would work better than “consumer” drives has not been true in our tests. I analyzed both of these types of drives in our system and found that their failure rates in our environment were very similar — with the “consumer” drives actually being slightly more reliable.