HDD Size and Performance

[Ruger22C]

It was said to me, that the larger the HDD the better the performance will be becuase the platters will be larger..
i.e., 160 gB vs 500 gB HDD, the 500gB will be much faster.

Is there any truth to this claim?

Thanks.

Moved to appropriate forum - Moderator Rubycon

 

[Aberforth]

In theory yes - because the data will be much denser compared to drives with lesser capacity but big ones usually have multiple platters so it doesn't make any difference.

 

[CycloWizard]

As Aberforth mentioned, since the radius of the platters is fixed by the physical size of the drive, there are two variables that can be used to increase the size: density of the bits and number of platters. Obviously, the number of platters will also become limited by the mechanical size of the drive's enclosure, so this sets an upward limit on the number of platters. The density of bits on the platters is set by a few different, interacting considerations: the ability to process the platter with bits at the specified density, electromagnetic interactions between the bits as they become very close together, and the ability to control the read head when trying to differentiate between bits. All of these things will influence performance to varying degrees. For example, if the bits are closer together, the head doesn't have to travel as far to read consecutive bits. Improved control drops the time required to find the bit you're looking for.

There have been a lot of patents recently on the motor/control side of things recently, and a lot of work on the processing end. I'm not sure how close the technology is to being limited by electromagnetic interactions at this point.

 

[bobsmith1492]

Originally posted by: CycloWizard
As Aberforth mentioned, since the radius of the platters is fixed by the physical size of the drive, there are two variables that can be used to increase the size: density of the bits and number of platters. Obviously, the number of platters will also become limited by the mechanical size of the drive's enclosure, so this sets an upward limit on the number of platters. The density of bits on the platters is set by a few different, interacting considerations: the ability to process the platter with bits at the specified density, electromagnetic interactions between the bits as they become very close together, and the ability to control the read head when trying to differentiate between bits. All of these things will influence performance to varying degrees. For example, if the bits are closer together, the head doesn't have to travel as far to read consecutive bits. Improved control drops the time required to find the bit you're looking for.

There have been a lot of patents recently on the motor/control side of things recently, and a lot of work on the processing end. I'm not sure how close the technology is to being limited by electromagnetic interactions at this point.

I think the much-touted "perpendicular" method pushed the theoretical density way ahead...

 

[imported_wired247]

The main way to decrease access time is to increase rotational speed, thus reducing rotational delay, while the main way to increase throughput and storage capacity is to increase areal density. Based on historic trends, analysts predict a future growth in HDD bit density (and therefore capacity) of about 40% per year.[14] Access times have not kept up with throughput increases, which themselves have not kept up with growth in storage capacity.

http://en.wikipedia.org/wiki/Hard_disk_drive

 

[Golgatha]

Originally posted by: Ruger22C
It was said to me, that the larger the HDD the better the performance will be becuase the platters will be larger..
i.e., 160 gB vs 500 gB HDD, the 500gB will be much faster.

Is there any truth to this claim?

Thanks.

Moved to appropriate forum - Moderator Rubycon

Keeping everything else constant, the density of the platters is what matters.

e.g. 2x250GB platters = 500GB = 1x500GB platter. The 1x500GB platter drive will read faster and thus have better performance characteristics even though the capacities are equal.


However, just because a drive is of larger capacity doesn't mean it will perform better.

e.g. 2x320GB platters = 640GB

1x320GB platter = 320GB

Both drives should have nearly identical performance due to the density of the platters being equal, with the 640GB drive only having a higher capacity.