How does a HDD write data on multiple platters?

[tompson]

Ok here is the next question for the pros.
A hard drive with multiple platters I wonder how the data gets distributed among them. Will the drive fill up platter 1 first then 2, 3 etc. Or do all heads write simultaneously. Can they move and write independent from each other or do all heads always move together at the same time?

Last edited by tompson on July 16th, 2015, 9:18, edited 1 time in total.

[jermy]

1) please don't open a drive outside of a clean environment.
2) please don't practice on a client's drive

[tompson]

1) please don't open a drive outside of a clean environment.
2) please don't practice on a client's drive

This is just a general question. I have no plans to open a drive on my own.

[Dmitri]

Check the head stack photo here and decide for yourself whether heads can move independently:

http://hddscan.com/doc/HDD_from_inside.html

[lcoughey]

Heads are all connected to a single arm and move at the same time. How the data is distributed throughout the platters depends on the brand and model of the drive. I've never encountered a drive that works with one full platter at a time, but have seen Samsung use very large portions (10-20GB) on a single platter before switching to an alternate surface. Most tend to use fairly small chunks.

[LarrySabo]

@tompson, have a read of this article by HDDScan: http://hddscan.com/doc/HDD_Tracks_and_Zones.html

[fzabkar]

You can see the serpentine nature of platter traversal in HD Tune, at least for those drives which implement Variable Bits Per Inch.

How to determine number of heads using HD Tune:
http://www.hddoracle.com/viewtopic.php? ... 650&p=1796