Do hard drives fail from open covers?

hepa

Modern drives are available at up to 100GB on a single platter.

There's nothing you can do in your home that will make it safe to open a drive, the moment you crack the seal, the drive is junk. If it doesn't fail immediately it'll fail within months.

I've opened a lot of dead drives to harvest the magnets and it's true, older drives which are often smaller as well typically have more platters than newer drives. I took apart a 4 gig SCSI drive once that had 7 platters in it and it seems like I once opened a 1 gig 5.25" SCSI drive that had 10-13 platters.

Are you suggesting that small, old drives have more platters than large, old drives?

Are you suggesting that the typical number of platters is decreasing? I cannot imagine why.

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The number of platters has been decreasing for a while. New technology allows getting many more bits per unit area on the platter surface, reducing platter count reduces costs for the platters, heads, motor size, head drive coils, etc.

The BIOS settings for platter/head counts now are pretty much not reflective of actual hardware inside the case.

JazzMan

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Because designers get better at higher density.

Look at floppy disks. 8" were relatively small capacity, though

5.25" when introduced were far smaller. 180K, more or less for the first generatiion of 5.25" floppies. They make them double-sided, and capacity doubles. They increase the data rate, and density increases. Then they move to the smaller 3.5", yet those started out at 360K for single sided, and double that when double sided came along. They bumped up to 1.44Meg, and of course there were even 2.88Meg drives if you paid the money when they were available.

The biggest hard drive I've taken apart hasn't been bigger than 1gig, and I think it's more like a maximum of about 500megs. Generally they've been much smaller. And a good portion have been 5.25" drives. I may be exaggerating if I've found any with more than 3 platters, but I've definitely seen those, and I have 160meg Quantum in front of me that has 2 platters. So at the very least density has increased dramatically if one can get gigs of storage on 2 or 3 platters.

Checking a chart in an old book, it's easy to see listings for drives with 8 heads (ie 4 platters) with capacity of 60Megs, and even 20megs.

They just got better at making higher density drives. If that hadn't happened, the drives would be getting bigger as capacity goes up, rather than getting smaller. And cheaper, for that matter.

I suspect that 1gig SCSI drive, nice and thick, that I recently found in a Mac Quadra 950 and has a date of about 1994, must have a fair number of platters. That's still fairly large for the time.

Michael

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>

...

So if everyone wanted the same capacity as before, the number of platters would decrease. But users want higher capacity.

The reason for multiple platters is greater capacity and also because the electronics is so much faster. With multiple platters, the electronics do not have to wait as long for a single platter/heads to retrieve data.

Haven't used them for years and I just bought a 256 MB USB flash drive. The floppy disk drive is dead, at least here.

Current CDs/DVDs are the same size as a 5 1/4" inch floppy disk. Yes, of course the capacity is greater.

Consumers pretty much dictate how large a device can be, according to its usefulness/function. Consumers dictate how much space the computer can occupy. When the electronics gets smaller, if the consumer has the same amount of space, the consumer buys the same size, more powerful computer.

Have fun.

A hard drive of 100MB can be destroyed by exposing its innards to untreated air outside of a Class 100 (or lower) positive-pressure clean room. Considering that you're talking about drives with about 600 times that data density, the answer is a firm YES!

If you value the contents of a hard drive, and expect to have any hope of recovering same, never, EVER open the cover outside of the proper environment, with the proper clothing and the proper tools. Doing so, even in air that looks like it's "clean, dust free" to the human eye, can easily cause it to self-destruct in a very short period of run- time.

Whoever opened those covers is the one you have to blame for the sudden lack of functionality.

Keep the peace(es).

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Yes, because data densities, in terms of bits per square inch, has increased dramatically as storage technology has progressed.

I once opened an old CDC 'Wren' SCSI drive. 5.25" full-height form factor. It had at least ten platters in it, at least 20 heads to match (one on each side, each platter), and a max capacity of less than a gig.

Years later, I opened up a more modern 4 gig 3.5" form factor drive (a Seagate 'Hawk' if I recall correctly). It had four platters and eight heads, yet it had several times the capacity of the much older and larger Wren drive.

That's because you're not taking into consideration the improvements over the years in magnetic coatings, and the significant advances in disk head technology. Both factors have greatly increased available recording density within a given space.

None of us can force you to believe anything, nor do I think anyone would presume to try. I know what I've seen, I know what I've read, and I know it to be the truth. If you choose not to believe it, that's your privilege.

Keep the peace(es).

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Think RLL 40 MB drives. :)

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But technology is changing so fast that indeed, a drive that appears similar on the outside may have a different bit density on the platters.

Yes. Besides that, the faillure rate on those Maxtor drives seems a bit above average anyway.

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   Maarten Bakker.

You can read from the drive's serial number (2nd digit) how many heads a Maxtor drive has. Divide that by two and round upwards to the nearest integer number to know the number of platters. No need to destroy a drive for that. By the way, there is a small chance the drives failed because you didn't tighten the cover screws with enough torque. Might try that before tossing them.

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   Maarten Bakker.

They have been, mostly before the IDE interface was introduced. Some early IDE drives reported the true number of heads/sectors as well.

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In sci.electronics.repair on Sun, 07 Aug 2005 02:37:07 GMT John Doe posted:

Oh, please. The context was that of a guy who opened 3 new drives to see how much data they held. The point of the first remark quoted above was that you can't tell that way. It wasn't a comprehensive statement about all hard drives, their capacity and the number of platters.

Didn't you and John Doe notice this? Why bicker?

Meirman

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You're reading way too much into what I'm saying. All I'm suggesting is that older drives typically have more platters than newer drives, and it's because of much lower data density on the platters. I didn't see single platter drives until just a few years ago, before that they almost always had 2-4 for typical consumer sized drives.

The typical number of platters has been decreasing because platters, heads, and the associated electronics cost money, as soon as they can bump the data density up high enough to reduce the number of platters they do it, that's why 120 gig drives which are currently the largest single platter drives available are also generally the lowest price per gig.

Yikes, that's more platters than I've ever seen in a drive. Those magnets are incredible though, I have a couple of similar ones on my refrigerator, you have to slide them off the edge to remove them or they warp the sheetmetal. Watch your fingers around them too.

and

Don't even get me started on that one, probably half the dead drives I've harvested have been Maxtor, I'd never buy another one. For a couple years Western Digital was making some real crap too, but they seem to have improved remarkably.