Why do hard drive manufacturers use half the hard drive?

[James]

I got 23 computers from HazMat when they closed in a town near where I live.
I got them to rebuild and sell.
They gave me a box full of 3.2 Gig hard drives.
When I format for reuse, I find that they are actually 6.5 Gig HDs.
Of course as I am formatting them, in the final stages of the format, FDISK starts trying to recover allocation tables on the HD. Always at the back end of the disk.
When I FDISK the HD and hit 4 for info on the HD, only 50% of the hard drive has been used. They are 6.5 Gig HDs.
They are labeled as 3.2 Gig but are actually 6.5 Gig.
Has anyone seen this before?
They seem to all come from Compaq Computers, as they have the Compaq Screws in the HDs.
I think Compaq bought hard drives that had bad places on the back side of the disk, and the HD manufacturer only used the front side of the hard drive disk so they could sell them.
They are all Western Digital Hard drives that are this way.

[Apoptosis]

never seen that before personally.

[Sovereign]

Very weird, can you open one and look? Otherwise, you got some defective drives IMO.

[James]

never seen that before personally.

I am starting with the 50% point of the disk size and am slowly progressing in formatting more of the hard drives.
I am going to see just how far I can format each one of these HDs.
I am working on one right now to see if I can get 5 Gigs out of it.
This is going to be a learning experiance for me.
I have never in all my years of messing with computers seen this.
I'll be sure and keep you informed on how this strange event works out.
I have about 20 of these HDs. I would like to make 6ers out of as many as I could.
I am installing 2 HDs in each computer that I am rebuilding as to give them a little more disk space.

[James]

never seen that before personally.

I am starting with the 50% point of the disk size and am slowly progressing in formatting more of the hard drives.
I am going to see just how far I can format each one of these HDs.
I am working on one right now to see if I can get 5 Gigs out of it.
This is going to be a learning experiance for me.
I have never in all my years of messing with computers seen this.
I'll be sure and keep you informed on how this strange event works out.
I have about 20 of these HDs. I would like to make 6ers out of as many as I could.
I am installing 2 HDs in each computer that I am rebuilding as to give them a little more disk space.

I have tried on 4 HDs on 3 differant machines and come up with the same thing on all tries.
The HDs will not format past the 50% mark without trying to recover the allocation units.
Once I drop back to 50% of the total disk space, they format out with no problem.
This has me curious. I must do some internet searching on this one.
My question is, Why would a HD manufacturer label a hard drive with half the disk space on the label? Why would they sell a HD that will not format past the 50% mark of MBs?
This is only on the Western Digital HDs from Compaq computers.

[Apoptosis]

Are you doing low level formats? If not I'd download Data Lifegaurd or WDDIAG and give it a try. WDDIAG.EXE is the best program to use when doing low-level formatting of your Western Digital IDE hard drives. It should be used with all Western Digital IDE hard drives, except the following: AC140, AC160, AC280, AC2120, AC2170, and AC2200. (For these drives, use WDAT_IDE.EXE).

Head on over to WD's Support site and download the version you need: http://support.wdc.com/

Low Level Formatting is the only thing I'd do on unknown hard drives. I use the Write Zeros To Drive function to take WD hard disks back to "bare metal" when the software is hopelessly screwed-up, to fix boot tracks, to remove overlapping partitions, and to test new drives before installing software. The Write Zeros to Drive function will destroy all data on your hard disk and give you a true fresh drive.

[killswitch83]

Man, I'm with you Apop, that is something I've never seen before, except in the instance where part of the HD (usually close to half) had been allocated by the manufacturer for the System Save partition (automated Restore in newer computers). But these partitions can easily be disposed of, so it almost sounds like to me that compaq physically manipulated the drives to only utilize half of the actual space. That's PC manufacturers for you.

[James]

Man, I'm with you Apop, that is something I've never seen before, except in the instance where part of the HD (usually close to half) had been allocated by the manufacturer for the System Save partition (automated Restore in newer computers). But these partitions can easily be disposed of, so it almost sounds like to me that compaq physically manipulated the drives to only utilize half of the actual space. That's PC manufacturers for you.

These hard drives will not and do not format after the first 50% of the disk.
This is not a Mobo situation.
Compaq, I do not beleave, had anything to do with the way Western Digital set up the HDs But I do beleave they were aware of it.
The labels say 3.5 Gigs. But FDISK sees 6000+ Mbs.
In my years of experiance with HDs, if FDISK searches for allocation units,the HD is soon to be history.
When I see that in a format, I pitch the HD.
What I do not understand is why the HDs were put into computers in the first place.Were they a bad run? Were they defective in the manufacturing process and sold as 3.5 Gigers to salvage a loss?
By all rights,in my way of thinking, they are defective.
I may be totally wrong, but I beleave if the HD will not read or write on the last half of the allocation units it is defective.
DOS FDISK sees 6000+ MBs. But they can not be used beyond 3.4 Gigs.
Why?
I have never seen this, ever.
I would appricate input on this.
It is truely strange.

[James]

Are you doing low level formats? If not I'd download Data Lifegaurd or WDDIAG and give it a try. WDDIAG.EXE is the best program to use when doing low-level formatting of your Western Digital IDE hard drives. It should be used with all Western Digital IDE hard drives, except the following: AC140, AC160, AC280, AC2120, AC2170, and AC2200. (For these drives, use WDAT_IDE.EXE).

Head on over to WD's Support site and download the version you need: http://support.wdc.com/

Low Level Formatting is the only thing I'd do on unknown hard drives. I use the Write Zeros To Drive function to take WD hard disks back to "bare metal" when the software is hopelessly screwed-up, to fix boot tracks, to remove overlapping partitions, and to test new drives before installing software. The Write Zeros to Drive function will destroy all data on your hard disk and give you a true fresh drive.

Mostly they are Caviar 23200s, or so the label says. But it also says they are 3.5 GBs.
If the HDs can be formatted to be 6Giggers I want to do that.
If I do this, will I able to recover the lost allocation units?
I will try this and let you know. Thanks for the input!

[kenc51]

did you write Zero's to the drive as Apoptosis said?

This returns your drive to a RAW state.
Looks like the drive was formatted with a hidden partition
Some OEM's do this, they then can install all the CAB files from your OS to here

Writing zeros to the drive will delete everything no matter what it is.
after you write zeros to the drive, use Disk Manager in XP to create a new partition

If I do this, will I able to recover the allocation units?

YES, Formatting the drive creates the allocation units.
Writing zeros to the drive will delete everything. When you format and activate the drive again it should hopfully give you something close to 6Gigs

Also make usre there is no strange jumpper config on the drive
I haven't much experience with WD drives, but the few i have seen were all old 8-10GB drives.. They had a strange jumpper config, I didn't take much notice as worked first time..

Hope this helps!

[James]

Man, I'm with you Apop, that is something I've never seen before, except in the instance where part of the HD (usually close to half) had been allocated by the manufacturer for the System Save partition (automated Restore in newer computers). But these partitions can easily be disposed of, so it almost sounds like to me that compaq physically manipulated the drives to only utilize half of the actual space. That's PC manufacturers for you.

Life IS too short to buy cheap parts.

[James]

did you write Zero's to the drive as Apoptosis said?

This returns your drive to a RAW state.
Looks like the drive was formatted with a hidden partition
Some OEM's do this, they then can install all the CAB files from your OS to here

Writing zeros to the drive will delete everything no matter what it is.
after you write zeros to the drive, use Disk Manager in XP to create a new partition

If I do this, will I able to recover the allocation units?

YES, Formatting the drive creates the allocation units.
Writing zeros to the drive will delete everything. When you format and activate the drive again it should hopfully give you something close to 6Gigs

Also make usre there is no strange jumpper config on the drive
I haven't much experience with WD drives, but the few i have seen were all old 8-10GB drives.. They had a strange jumpper config, I didn't take much notice as worked first time..
Jumpers are setcorrectly.

Hope this helps!

[kenc51]

mayby i should read the full tread b4 commenting!


Did you write zeros ??

[James]

mayby i should read the full tread b4 commenting!


Did you write zeros ??

I used a WINME start up floppy to format the hard drives.
That is the way I have always done it.
FDISK - Format.
A: to C:
C: format C: enter.
All data on C: will be lost do you want to continue?
Y enter
FDISK formats the hard drive.
FDISK checks the drive before format.
The disk checks good. The only problem is recovering the allocation units with FDISK format.

[jigr69]

This could be an exercise similar to a very early computer manufacturer called Sinclair back in the 80's. They produced computers called ZX Spectrums (I don't know if they were available in the USA), which basically had faulty memory chips installed.

The memory chips consisted of a lower and upper half, of which the memory manufacturer would trash any which failed in either section. Sinclair would buy up these 'faulty' memory chips at a very cheap price (compared to the cost of a fully working one), and tested to see which half of the chip had failed. The chips were separated into two bins, and the computers as they were being built had the memory installed only from the same faulty memory bin. So a computer had memory chips which had a fault in the lower section only, or in the upper section only, but not both. A link would then be inserted into one of two positions depending upon the memory installed. This would force the computer to use only the good half of the memory.

So essentially Sinclair ZX Spectrums had double the memory installed, but could only use half of it! If you bought a 16K version and wanted to upgrade it to a 48K version, you would had to buy the original memory (not faulty memory) as that way it didn't matter which half of the memory module the computer was set to use.

Back to your hard drives, I think Compaq have done something similar, whereas instead of it being memory that was at fault, it a platter of the hard drive. The reason why you are only seeing this on the second half of the drive is that if the first two tracks on a hard drive is corrupted, then the whole drive is no good, regardless of the size. They may even arrange in production of the drive to ensure that the fault platter is the second to be used. This way Compaq can buy a load of 3.2GB drives at a cost much lower than they would have been, thus reducing the cost and increasing the profit margins on every computer fitted with one.

I've even heard rumours of a graphics card maker employing a similar method to Sinclair in order to lower production costs of graphic cards. Although it was some time ago when graphic cards were considered top notch with 32MB installed! Unusual and a rare occurance, but not unheard of!

[killswitch83]

hmm, a flawed platter near the end of the drive? That's something I didn't even think about. No wonder Compaq had such a high rate of return back in the mid to late 90's for bad HDD's. I remember when they used the Quantum BigFoot drives in their systems...said the larger platter size would enable them to gain higher capacity on their disks. What they didn't realize is that the larger the platter, and the faster it spun, the more prone they were to suffer head crashes, flawed platters, and the such. I know CTX used to practice the same method that you just mentioned jigr (back around the same time Compaq had their woes). Good call

[killswitch83]

That would also explain why some of the Compaq's came back with defective MBR sectors, and were DOA.

[James]

hmm, a flawed platter near the end of the drive? That's something I didn't even think about. No wonder Compaq had such a high rate of return back in the mid to late 90's for bad HDD's. I remember when they used the Quantum BigFoot drives in their systems...said the larger platter size would enable them to gain higher capacity on their disks. What they didn't realize is that the larger the platter, and the faster it spun, the more prone they were to suffer head crashes, flawed platters, and the such. I know CTX used to practice the same method that you just mentioned jigr (back around the same time Compaq had their woes). Good call

I have one of the Bigfoot HDDs.
They are selling for about $250.00 on the internet. They are hard to find computer parts now.
I guess some of the older equipment the some companys are still using still need them.
They were a fast hard drive in their time. I will probably just keep it.
Like my older computers running WIN3.1, I just can't seem to let em go.

[James]

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[Apoptosis]

I called one of the engineers at western digital and left a voice mail.... I'm working on it now ;)

phonce call returned... dang took him 20 minutes to call me back and he's off work... LOL WD has some really good people workign for them and I called in a favor for this one. My WD Contact wants to know a couple Serial Numbers off your drives and their model numbers (are all the same?)

Many Thanks