Manufacturer's hard drive short stroking method?

Hi guys,

So I've been pondering and trying to do some research on short stroking hard drives for performance which can simply be done with a good hard drive speed measuring software such as HDTune and partitioning the hard drive for performance on the user end.

But what are the details and method used for short stroking hard drive from the manufacturer?

A good example would be a 500GB Barracuda 7200.12 which is a single platter drive while the 1TB 7200.12 is a dual 500GB platter drive but a 750GB 7200.12 would also be a dual 500GB platter drive short stroked in the firmware which only allows access to 750GB of the 1TB.

How is the manufacturer short stroking the platters on a 750GB 7200.12 hard drive, are they simply short stroking the drive as whole which means only the the second 500GB platter is limited to 250GB or are they short stroking each platter together limiting each 500GB platter to 375GB for a total of 750GB?

The latter of short stroking each platter to 375GB in the example above if done by the manufacturer would be preferred method since it would limited the head to only read data from the outer layer of the disk platter two in the case of the 750GB 7200.12 thus improving the overall reliability of the hard drive while still taking advantage of performance gains from short stroking.

I'm very curious...thanks if advance

 

Hard drives use a moving head to write and read data. So if we think of a hard drive like those old music records, the head is like the needle in the record. It takes time to move that head to a different track. OK, the next thing to know is that for anything spinning, the outside will be moving faster than the inside.

So for a hard drive, we can read/write data fastest on the outer edges, and when that fills up, then move the head in to the very next closests track.

Short stroking is simply using just the outer edge of the hard drive platter. So yes, it is platter specific. By just using a small outer edge, the read/write head only makes short strokes on the outer edge.

OK, now that we understand it, I don't recomend it. You lose a good portion of the hard drive. If you can afford to lose that much, then get a SSD. Second, when a hard drive fills up, it will mostly fill up the outer tracks first. Third, you can get good hard drive defrag software that will optimize your most used software into the outer tracks. Good defrag software will even organize two software that are frquently read together, and put them seqentially on the hard drive. Lastly, I have seen no data that the hard drive will last longer. The head servo is magnetically driven, so it won't wear out for a long time, the spinning hdd on the other hand...

 

Short Stroking... highly recommended.

Get the biggest drive you can with as many platters as possible (this will give you the most capacity at the fastest speed once it's 'stroked).


See:
http://forum.notebookreview.com/har...-hitachi-7k500-benchmark-setup-specifics.html



Hope this helps.


(But I agree: get an SSD if you really want max performance (but remember that you'll have to short stroke the SSD too...).


Good luck.

 

Short stroke the SSD?

 

Yeah; that's what it is, but it is accomplished by leaving at least 30% (my recommendation) as 'unallocated'.

See:
http://forum.notebookreview.com/sol...arks-brands-news-advice-1066.html#post9317068

 

Ah, not exactly short stroking, but a way to extend the SSD life. Which is out of scope for this thread, unless the OP has a concern...

 

LOL tilleroftheearth the correct term for SSD's is over-provisioning and yeah I'd also recommend leaving at least 30% unallocated of free space specifically on Plextor M5 Pro's, 25% for Samsung 800 series and 20% for Intel 500 series.

 

Only over-provision SSD if you do a LOT of writes (like hundreds of GB's a day). Most users do not fall into this category. Performance won't be affected otherwise. If you decide to over-provision, I don't think anything over 10% is beneficial. Heck Samsung even recommends no more than 10% OP on their drives in the Magician software. There's 99% of users out there with SSD's who are none the wiser and haven't over-provisioned at all and are using their SSD's perfectly fine. And yes, opt for SSD over HDD especially if you're looking for max speed benefit from an HDD, because you really get the most speed benefit out of about the outer 20% of the drive, so for a 1TB that's only 200GB, and it's still a far cry from any SSD you use.

 

Yeah, it is exactly like short stroking: you limit the drive to less capacity than it nominally has.


As for not needed except in high write scenarios... I disagree. If you want the fastest, most responsive system no matter how you use your drive, I have found 30% unallocated as a minimum in mine and my clients setups.

Even Anand recommends 25% unallocated for best, sustained (over time) performance.


See:
AnandTech | Exploring the Relationship Between Spare Area and Performance Consistency in Modern SSDs

 

Let get back onto short stroking, HTWingNut nailed right on the ball with not going over 20% on a mechanical hard drives total capacity (unformatted) for best performance when short stroking.

Here's a link of an article that I've read on short stroking mechanical hard drives: Accelerate Your Hard Drive By Short Stroking - On The Stroke Of Performance: Hard Drive Short Stroking

And thus why I was asking and comparing just simple user partitioning short stroking method's performance compared to a utility or short stroking done via firmware.

 

From memory, the SS with firmware purposely limits the LBAs that can be accessed so its completely software agnostic (i.e. deployments for exotic applications). As for performance, it is no different to making smaller partitions seeing as they are simply two different approaches to the same goal.

Obviously, it would be in the interest of the manufacturer to use firmware to shortstroke as factors such as product differentiation come in to play (i.e. using a single physical design for multiple SKUs), this is especially seen in the enterprise space.