But really, who wants a 15,000rpm velociraptor to be turbo charged to a 'simulated' 30,000rpm? Format was already changed making the velociraptor, they could easily cram in another arm without making the drive longer than standard

Because today instead of a Dual Actuator/Head setup, we use two HDDs in a RAID setup.

Cool Article, Keep it up Toms!

So we just have to ask and the answer will be revealed?!?

"Why do hotdog buns come in packs of 8 when hotdogs come in packs of 12?"

(but really, nice article)

That first Seagate implementation isn't even what comes to mind. What I mean, is if you have one read head that does half the platter, and another for the other half then you can only increase the transfer speed if your data is completely randomly scattered. This would not help sequential reads whatsoever.

Now who would want to run a 5.25" HDD? Maybe stick two sets of platters from 2.5" drives in there and see what happens. Technically its dual actuator... Implement a RAID controller onboard and see what happens.

To force OCD people to buy 2 packs of hot dogs and 3 packs of buns whenever they want a hotdog, duh!

Just eat your hotdogs on regular sliced bread, problem solved.

Not to derail the thread further, but the hotdog buns come in packs of 6 or 12 where i come from (QC, Canada).

Nice article.

Make up your mind!

The spec's say 15.700rpm and as any one can see so way the model indication why do you guys at toms keep calling it a 15,000rpm drive ?

I have another question. Why don't all heads read in parallel?. That would not reduce rotational delay but it could increase throughput.

Very interesting article and nice pics of both the drives and the blue-prints. Not like the usual crap from Jane McEntegart.

Because Seagate says it's 15,000 RPM?

http://www.seagate.com/docs/pdf/ma [...] _15k_7.pdf

And the ".7" in 15K.7 doesn't represent "15,700" RPM.

/ Tuan

Good article, great images. Well done Tuan.

I was wondering this too. Why can't they then use laptop platters in desktop HHD's with dual arms? might work. I think they should continue to look into this. I'm sure there are some people that would pay more for this. Oh wel, I just need to wait till SSD's get cheap now

this seems rather stupid honestly to me by the hard drive companys from what i understand a normal 7200rpm harddrive does somewhere around 75mb/s while the SATA 3.0 goes MUCH faster even if it cost $100 instead of $50 for a 500GB harddrive there are a lot of people that will pay that for 2x the speed and there are a lot that do by making raids i am right now planing to make a 4 drive raid in my next computer i have no need of more then even 500GB of total Harddrive space yet i am going to end up with 2TB of room instead buying 2 drives that were 2x as fast in a raid would of been somthing i would do with out a problem at all.

I stand corrected and thanks for the bit of extra information.

./me bows down

It would also raise failure rates......

a good rule to follow for when you get the idea "Hey a really good simple way to improve XX would be _______": somebody has already thought of it before and there is a good reason why it doesnt exist. usually the answer comes from following the money

Great article, Tuan! This is the stuff I read Toms for and of course, the usual reviews and interviews... the interesting stuff on toms

Thanks for the feedback guys!
More articles like these coming.
Hope everyone enjoys the weekend.

/ Tuan

I would say one dual head drive (eg: 500GB) would cost considerably less than 2 drives (2x250GB). It will run cooler,consume less, and will be about as fast as a raid setup of 2x250GB.

It will also be smaller in size,and could be made size compatible with normal 3,5" drives easily.

It would make sense for power efficient servers.
I can't speak of heat issues, but if you would program the driver of the disk to not have the 2 arms read/write on the same ring or sector, that may reduce performance little, but it might increase data accuracy.
Then again, if the ring has been preset, and would be a sector of about 500MB, the drive could be equipped with 256MB ram memory, that could buffer the data of the second arm (in case a linear file-read is preferred).

Anyways, as I hear it from seagate, it's a technology that never made sense back in the days, but today it does,and is easy to create.
I think it's perhaps a meager excuse why noone actually took time to further develop that theory or patent.
Instead, they buy a patent and not use it? What good does that do?

If there's ram to buffer it could increase speeds as the first arm could read the first eg:500Mb of a movie, while the second arm continues filling a RAM space from 500 to 1024MB. This would give a slightly slower start, but end up in speeds about 2x current speeds.

The dual head drive would actually be faster than 2 raid'd drives in terms of seek time, which is what actually matters in enterprise storage, raw throughput wouldnt obviously be as fast, but since its bigger anyhow, why not instead work on the materials necessary to spin the ultra-high-density platters up to 15k instead of 7200rpm? --> this would simultaneously increase throughput and seek times. (yes throughput is directly related to the disk density)

Yeah, it may have been difficult in 1996, but this is a cop out with today's tech ! Tuan, please call them on this BS and ask them to give us a reason that is concurrent with 2009. Technologically this should be easy today.

Interesting point guys.

I'll talk to Seagate and see what they say about implenting such a technology using what's available and possible today.

/ Tuan

this is the reason why this thing won't work..

http://www.tomshardware.com/news/d [...] ,8115.html

http://www.seagate.com/ww/v/index. [...] ge=Legacy#

We actually ordered some of these where I worked in the early 90s.
After a few months, all of them had failed (and the same problem occurred at several other places using these drive). Seagate never managed to get the mechanical problems sorted out and the drive was cancelled.

All the units we had ordered was eventually replaced by more standard drives that actually lasted more than a few months....

Excellent article. I always thought it would be really cool to have a 'multi-threaded' harddrive, but not for the reasons listed above.

I think it would be nice to be able to access two things on the hardrive in a truly simultaneous manner, e.g. viewing photos while copying a large file, without the random access interrupting the sequential access.

The problem is that, to really do this properly, you would need dual connections between the motherboard and the dual-head drive with both heads accessing the entire drive independently. This would require modifications to the motherboard, BIOS, operating system, etc.

Lastly, I’m not surprised by TNM’s comments above. The extra parts would drastically reduce the Mean Time to Failure of the drives.

I think that by the time this technology could be redeveloped to anything useful, SSD drives would have increased their speed and capacity and lowered their $/GB to levels so low that this technology would never be able to compete.

You crazy Canadians and your logical packaging design!

I agree.

I still think seagate dosn't have a good answer to this. From a engineering standpoint it is very doable. The technical drawings of the original patent show 2 actuators/heads reading from the same platter. This is not needed in a current HDD, with 500GB per platter technology availible you could, in theory, have a 2 platter design capable of 1TB total storage and have a independent actuator/head for each platter. Like others have said this would be similar to RAID 0 in performance. As far as price goes, it would not add near as much cost as a SSD of similar capacity but reliability would be my main concern.

As you said blackened, at this time, development of somthing like this would be very time consuming and by the time a prototype was ready SSD's will be a much more viable solution.