Partial-stroking / Short-stroking / Half-stroking Hard Drives?

Short-stroking is basically what you found. You specifically use only the last few tracks on each platter of your hard disk. I have heard of this, but haven't looked at it in a while.

Looking at new articles, as well as from memory, the details about this are a mixed bag, mainly bad from my perspective.

• Extremely reduced capacity for the drive because short-stroking only shows a benefit with very small "drive" sizes.
• Roughly 40% better random seek times.
• Slightly faster bulk transfer rates.
• Requires specialized software that doesn't seem to be widely available.
• When used in a RAID 0 array (as most articles recommend) this uses a lot of power for relatively small drive sizes.

I have previously recommended against ideas like this, as just buying larger, faster disks is cheaper in the long run, unless you don't pay for your electricity. The time savings may help in a database server with very little memory, but I can think of no other situation.

In general reading from the outside sectors of the platters is faster, as more sectors pass under the heads per second at 7500 RPM (or whatever) than towards the middle. Also, the heads rest on the outside of the drive when resting so, making a partition only near the center of the drive could actually give you worse seek speeds.

In the beginning each "track" of a disk platter had the same amount of 512 byte sectors - meaning the density was highest towards the center. This was as I understand it pretty early on improved by making each track have a variable amount of sectors to increase efficiency and have about the same density over the entire platter (ZBR).

Hence, the further out on the platter data lies, the faster it can be read and written to as the raw throughput will be higher.

So yes, partitioning only the outside half of a disk would definitely increase overall performance.

Is it worth it? No idea. It's usually employed for high-end 15krpm drives in critical environments. Today I'd say the modern drive controllers in these situations can handle this intelligently enough without specifically "short-stroking" drives.

I'd be curious to know if this is used "at factory" as well, like producing smaller-sized high-speed drives with perhaps more than one platter that only internally uses the most outer tracks to get a performance advantage?