Thinkpads Forum

Seagates new 5400.3 160GB drive with perpendicular recording looks kind of interesting for packing the most storage capability into a laptop.

Just wondering if anyone has purchased one of these drives and can give us their impression. Kind of pricey right now though.

http://www.newegg.com/Product/Product.a ... 6822148073

In one of the 3 articles below, the reviewer mentioned that the Seagate 5400.3 160GB HDD use "glass" platters" instead of "aluminum" platters, with negative connotations.

I'm not sure what disadvantage(s) glass platters have over aluminum platters, as the older HDD's seemed to use glass platters before (again, by the reviewer).
Perhaps the magnetic materials fall off the glass platters easier near the end of its useful life (ie: one bad sector quickly makes more bad sectors)...


http://www.tomshardware.com/2006/03/03/ ... icroscope/
http://www.laptoplogic.com/reviews/deta ... ull&page=1
http://www.anandtech.com/storage/showdo ... i=2682&p=1

I didn't see any mention of glass in the above reviews. I think it's this page of this review that w0qj is thinking of:

http://www.xbitlabs.com/articles/storag ... 003_2.html

A curious material indeed to find in a hard drive.

Just looking around quickly on Google, here's a discussion of the shift in hard drives happening away from aluminum alloys and towards glass/ceramic composites.

http://www.storagereview.com/guide2000/ ... rials.html

In some ways (though not all), it looks like glass/ceramic should be more stable and reliable than aluminum. Apparently moving to glass/ceramic is also necessary, in order to be able to have thinner platters and continue to increase the capacity of hard drives in their given form factors.

Glass and Ceramic materials are being used more and more to lay down the media substrate on the platters; currently, however, there is but a tiny shortage of glass for such HDDs as they have to be specially processed by either the supplier or the HDD manufacturer; depends on the company making the HDD. Not much of a problem, though, considering how many HDDs get shipped everyday.

donking! wrote:...I think it's this page of this review that w0qj is thinking of:

http://www.xbitlabs.com/articles/storag ... 003_2.html
...

Thank you! Yes, that's the link i had in mind...

"...we see an adhesion layer and something else with a mysterious name “Substrate”. I believe here some of you will be astonished: this is a layer of glass!

Everything returns to its natural roots, and we see glass coming back to the hard disk drive industry. We only hope that the new generation adhesion material will boast better adhesive features to connect glass and metal layers."



***I guess from above one can conclude that older HDD's many years ago were made of glass, but replaced by aluminum platters for their better characteristics...


***Glass seem to have more difficulty in holding magnetic materials than aluminum, as above link.

I think this is a greater potential disadvantage (especially hear end of HDD's life) than the potential advantages of glass (better smoothness, better rigidness, etc.)

I mean, if glass is more rigid than aluminum, designers would be sorely tempted to just make the glass platter thinner (like your 2nd link suggests), then glass would be back at square one-- it has trouble holding magnetic materials, thinner glass platters more fragile than aluminum ones, and other qualities same [due to glass platters made thinner than aluminum ones]).

I came across this in one of the other threads http://forum.thinkpads.com/viewtopic.php?t=21439:

mrpaulin wrote:I've used the new Seagate 5400RPM 160GB drive in my T41 in both the Ultrabay Slim HDD adapter and also in the internal bay. There are no issues to report with either configuration.

For that matter, it also works fine in an Ultrabay 2000 HDD adapter in my A31P as well as in my Dock and my Dock II.

Hope it helps,

regards Zed.

w0qj wrote:I mean, if glass is more rigid than aluminum, designers would be sorely tempted to just make the glass platter thinner (like your 2nd link suggests), then glass would be back at square one-- it has trouble holding magnetic materials, thinner glass platters more fragile than aluminum ones, and other qualities same [due to glass platters made thinner than aluminum ones]).

I think it's probably pretty hard at this point to know what the reliability benefits/disadvantages are going to be.

The Storage Review discussion of glass/ceramic platters does suggest that these composites may some day be no more fragile that aluminum platters. It also mentions thermal stability as an advantage they have (in addition to the questions of rigidity and smoothness you mention). So, who knows, maybe some day these platters will be all around better. But then again, maybe not.

It's curious that Storage Review doesn't mention the adhesion issue that X-bit labs brings out.

Still, in the end, the biggest problem is that there is such poor data on reliability in actual practical use. It's hard to really even know what the relative reliability is of the aluminum drives we all have now. Unless there's some grotesquely different failure rate with glass/ceramic drives, we'll be stuck relying on our general impressions.