FAQ

Notebooks: The transition started with 2.5” notebook drives, starting with the largest capacity (750 GB)
new drive families in late 2010. The mainstream 2.5” capacities (250GB-500GB) for notebooks
transitioned to 4K sector (512e) in mid-2011.
Desktops: 3.5” HDD has ~3x the capacity point of 2.5” HDD so the demand of high capacity 3.5” HDD was
less than the 2.5” HDD. The transition occurred with the 4TB product introduction in 2012.
Enterprise: New products will have options for 512 native, 512e and 4K native models. This is to provide
seamless transition. By 2016, all new products will either be 512e or 4K native models. Legacy capacities
will be supported with 512n models until 2020.
7. How will 512e-disks affect our customers?
Customers who are using client 512e HDDs and use them with legacy OS and software will have
performance degradation and data integrity risks. See question 2 above for known legacy operating
systems that are not 4K aware. Most home-grown cloud operating systems have been designed to
operate with 4K native or 512e format.
8. How to mitigate performance degradation?
Early adopter client customers minimized the performance degradation of 512e HDDs by converting to
new OS and software that are “4K aware”. There is also third-party alignment software that reduces the
data misalignment on 512e HDDs in conjunction with legacy OS and software device drivers.
Currently, client systems are shipped with new OS that is 4K aware so the misaligned incidents are
reduced significantly. Some of the benchmarks (Jetstress) showed no performance concerns with client
systems using latest OS and later generation 512e drives.
Enterprise cloud customers have their own home-grown OS that converts the atomic operation to 4K
bytes sector so 512e and 4K native drives can be easily deployed in these cases.
Traditional mission critical enterprise customers running traditional OS (Microsoft, Linux) and database
(Oracle, SQL) will have to align their disk partitions to avoid performance and data loss possibilities.
In addition, customers can choose to use the Enterprise version of 512e HDD with non-volatile cache
system to further minimize the performance degradation impact.
Customers can also choose 4K native HDD if their servers are using newer versions of BIOS/OS/Software.
This solution stack will have the optimal performance since the physical and logical sectors are matched.
However, it is limited to only the newer BIOS/OS/Software.
9. Is there data integrity risk during sudden power off?
If volatile write cache is disabled:
• For"512n"and"4Kn"HDD,"there"is"no"data"loss"during"sudden"power"off.
• Enterprise"512e"HDD"with"NVC"and/or"MBC/MC"feature"(see"question"5)"also"does"not"have"data"
integrity"risk.
8 4K Sector HDD FAQ