DreamPC 2006 ready for it's grave...

On 10/26/2011 12:35 AM, FatBytestard wrote:
You are a goddamned idiot. Shock is measured in Gs as well, you stupid
twit. That is why the drive makers publish their shock RESISTANCE specs
in Gs. And NO,you slamming a door shut on your case is NOT going to
surpass those specs. Get a ****ing clue, IDIOT!

I do have to give the idiot a little credit. He is parroting an old
truism from back in the old days of MFM/RLL days, **** like that did
happen back in the day. The old DOS "PARK" command *did* exist for a
reason.

Just tryin' to be fair....

(rant ON)

I *am* going to bitch about those hard-drive shock/G specs tho.

I've worked as a QC/proto tech on "stuffs" that have gone thru
shake-table testing for those ratings, including setting up the table
and sensors. It's just one of those things that have to be quantified
for MilSpec weapons systems and NASA gear, should be obvious.

I always saw (and interpreted from) those specs by the "qualifier" that
indicated how the "shake" was applied.

I've never seen a "qualifier" on a HD datasheet.

Think "100 watts peak music power" vs "100 watts RMS @ speced
distortion". I've seen (as have many) *cheap* 100W PMP units that can't
even do 5W RMS without blowing up.

See the "qualifiers"?





--
"**** this is it, all the pieces do fit.
We're like that crazy old man jumping
out of the alleyway with a baseball bat,
saying, "Remember me mother****er?"
Jim “Dandy” Mangrum

On Wed, 26 Oct 2011 02:49:29 -0700, "Nobody (Revisited)"
wrote:

I do have to give the idiot a little credit. He is parroting an old
truism from back in the old days of MFM/RLL days, **** like that did
happen back in the day. The old DOS "PARK" command *did* exist for a
reason.

Just tryin' to be fair....

But that was *way* before he was around.

I still have several MFM drives, and only the earliest lacked an
'auto-park' 'feature'.

From the prices I see on ebay for old legacy stuff, I should sell them,
because they are all fine.

But yes, they were/are far more vulnerable than today's 1.5" 15k rpm SAS
drive, which can boast 200Gs running and 300Gs in transport. Not that I
would ever subject any drive to shock numbers like that.

On Wed, 26 Oct 2011 02:49:29 -0700, "Nobody (Revisited)"
wrote:

I *am* going to bitch about those hard-drive shock/G specs tho.

OK

I've worked as a QC/proto tech on "stuffs" that have gone thru
shake-table testing for those ratings, including setting up the table
and sensors. It's just one of those things that have to be quantified
for MilSpec weapons systems and NASA gear, should be obvious.

Yes. Hard drives have military roots, and so did their manufacture,
before those standards were relieved. They *are* standard declarations
and there is a mil spec they follow.

I always saw (and interpreted from) those specs by the "qualifier" that
indicated how the "shake" was applied.

Depends on the maker as to how much data one will see declared on the
primary spec sheet. Some makers require further inquiry to 'extract'
certain figures from them.

I've never seen a "qualifier" on a HD datasheet.

I have, but they follow a standard, so standard practices would be
utilized. There is functional test, and then destructive level testing
where you shake it till you bake it.

Think "100 watts peak music power" vs "100 watts RMS @ speced
distortion".

Don't really need a primer, but environmental and vibe specs are
standardized. This industry (hard drives) is no exception.

I've seen (as have many) *cheap* 100W PMP units that can't
even do 5W RMS without blowing up.

I was around in the seventies, dude. I don't even want to talk about
the differences between declared and real audio amplification claims and
'specs'. I watched it walk from 1% THD being "good" to 0.004%, to now ,
where it doesn't seem to make so much difference and floats between 0.1%
and 0.01%. That was home stereos, and they *were* properly declared.
"Auto-sound", on the other hand, was typically not correctly declared.
"The smokin' is the tellin" as they say. I saw some really nice stuff
that was mounted right on the back of the speakers back in the mid 70s
that did a pretty good job, if the owner had enough brains to enclose the
backside.

See the "qualifiers"?

Well, you know it will be sinusoidal. One does not test assemblies
with hard, square wave vibrations.

On 10/26/2011 3:18 AM, FatBytestard wrote:
Well, you know it will be sinusoidal. One does not test assemblies
with hard, square wave vibrations.

Wanna bet?

I don't know how the Navy and/or the contractor noogied BuShips into it,
but one piece of Tomcat avionics gear got "that".

At least as spec.....

I don't know who (suspect someone at JPL) convinced them that God can't
even do that, but it finally came down as "sawtooth averaged to RMS" ?

We could do that, but nobody wanted to be within 100 feet of the table
during that.

Hey..... nice to find someone who knows this ****!

I did my shakey stuff at Eldec, Rocket Research, Pacific
Electrodynamics, and Sunstrand back in the early 80's.

Rocket had the "killer vibe-table". IIRC, it was 1KW "RMS?"each in X-Y,
and 2KW in Z.

--
"**** this is it, all the pieces do fit.
We're like that crazy old man jumping
out of the alleyway with a baseball bat,
saying, "Remember me mother****er?"
Jim “Dandy” Mangrum

On Wed, 26 Oct 2011 04:06:25 -0700, "Nobody (Revisited)"
wrote:

I don't know who (suspect someone at JPL) convinced them that God can't
even do that, but it finally came down as "sawtooth averaged to RMS" ?

I like it!

It would be fun to shoot a few rounds of pool and beer with you,and
reminisce.

It's called "slew rate". Nature, save for a bloody earthquake,
typically doesn't move like that. (unless the bucket of bolts you are in
is falling apart) :-)

On 26/10/2011 8:49 PM, Nobody (Revisited) wrote:
On 10/26/2011 12:35 AM, FatBytestard wrote:
You are a goddamned idiot. Shock is measured in Gs as well, you stupid
twit. That is why the drive makers publish their shock RESISTANCE specs
in Gs. And NO,you slamming a door shut on your case is NOT going to
surpass those specs. Get a ****ing clue, IDIOT!

I do have to give the idiot a little credit. He is parroting an old
truism from back in the old days of MFM/RLL days, **** like that did
happen back in the day. The old DOS "PARK" command *did* exist for a
reason.

The MFM/RLL days are well and truly extinct and that can only be a good
thing. Modern drives are nowhere near as delicate as those early drives
were.

Just tryin' to be fair....

The shock, if any, applied to a case door would be in the same
horizontal plane as the platter. As such, it is unable to cause a head
crash, just a horizontal movement of the head across the platter. Might
add that horizontal movement across the platter is what the heads do a
damn lot of in normal operation.

(rant ON)

I *am* going to bitch about those hard-drive shock/G specs tho.

I've worked as a QC/proto tech on "stuffs" that have gone thru
shake-table testing for those ratings, including setting up the table
and sensors. It's just one of those things that have to be quantified
for MilSpec weapons systems and NASA gear, should be obvious.

I always saw (and interpreted from) those specs by the "qualifier" that
indicated how the "shake" was applied.

Indeed. I had a drive in my NAS box crashed by a jerk who dropped his
laptop bag, complete with laptop, on the table where the NAS was
operating. That was a VERTICAL SHOCK, guaranteed to crash heads when the
drive is running. If the drive was not running, the heads would have
been parked off the platters.

I've never seen a "qualifier" on a HD datasheet.

Think "100 watts peak music power" vs "100 watts RMS @ speced
distortion". I've seen (as have many) *cheap* 100W PMP units that can't
even do 5W RMS without blowing up.

See the "qualifiers"?

Know them well....

--

Krypsis

Sources of shock:

1. Shutting the PC case door.

2. Bumping the table.

3. Picking up PC and laying it on table to work on it.

4. Pulling out HD tray's and moving them.

5. Pulling out HD tray's to clean fans on antec 1200 case.

6. Perhaps even fans, micro-shocks/vibrations.

7. Perhaps neighbours slamming floor or ceiling though less likely.

So there is not much choice of where the shock damage came from. I never
wrote that I was certain that it was a case-door slamming it shut, but it
could be, it's a potential source of shock. Therefore until somebody
precisely measures the ammount of shock, or g-force for you nobody knows.

Bye,
Skybuck.

On Oct 28, 11:33*pm, "Skybuck Flying"
wrote:
Sources of shock:

1. Shutting the PC case door.

2. Bumping the table.

3. Picking up PC and laying it on table to work on it.

4. Pulling out HD tray's and moving them.

5. Pulling out HD tray's to clean fans on antec 1200 case.

6. Perhaps even fans, micro-shocks/vibrations.

7. Perhaps neighbours slamming floor or ceiling though less likely.

So there is not much choice of where the shock damage came from. I never
wrote that I was certain that it was a case-door slamming it shut, but it
could be, it's a potential source of shock. Therefore until somebody
precisely measures the ammount of shock, or g-force for you nobody knows.

Bye,
* Skybuck.

So dump that piece of crap and move on to ruining your next 'dream'
machine.

G²

You are not very convincing by just insulting me, try to come up with some
real data/facts.

Insulting is easy, telling the thruth is not easy.

I personally do not care about any facts you may find because my harddisk
has bad sectors plain and simple.

Bye,
Skybuck.

The antec 1200 case door is detached, therefore it requires horizontal and
vertical movement to shut it closed properly.

Bye,
Skybuck.