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Old 15th June 2011
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rocket357 rocket357 is offline
Real Name: Jonathon
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Quote:
Originally Posted by nilsgecko View Post
As rocket357 pointed out however, it's possible that things are entirely implementation-specific. Interesting.........
That depends on if you buy what the author of zcav said in the link I posted above:

Quote:
Since the introduction of hard drive interfaces which seperate logical addresses that operating systems use from the physical storage on the device (this means SCSI, IDE, and any other high-level interfaces that might be out there) it has been possible for hard drives to have more sectors on outer tracks. This is done through a scheme called Zoned Constant Angular Velocity (ZCAV). In this scheme the disk is divided into a series of zones which each have different numbers of sectors and therefore different performance characteristics.

Apparently the convention is for the outside tracks to contain the sectors with lower addresses, so the first partition allocated on a disk is likely to be significantly faster.
That seems to be the case, at least in every hard drive I've ever tested...the lower logical addresses correspond to the fastest portion of the disk, which common understanding says are the outermost portions of the disk, since the linear read-head velocity is greater and the sector density is also greater*. Sure, seek time plays an important role, but if I were designing a hard drive, I'd optimize seek time over the fast portion of the disk so the disk would be as fast as possible until it started to fill up.

I could be wrong, but that's how I'd approach it.

* - The circumference of a given "track" on a platter grows as you move further from the center. This means 2 things: 1) The relative speed the head "moves" across the platter is greater (further to "travel" as tracks get larger towards the outermost tracks), and 2) each "track" has more distance to it as you near the outermost tracks, so outer tracks can contain more sectors (i.e. more data). Faster linear speed + more data = faster data rates.
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Last edited by rocket357; 15th June 2011 at 04:14 AM.
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