On 22/12/2012 14:19, tony sayer wrote:
In article , John
Rumm scribeth thus
On 21/12/2012 17:51, tony sayer wrote:
In article , John
Rumm scribeth thus
On 20/12/2012 13:33, tony sayer wrote:
WOC are good if you live near them and are going by there to pick stuff
up, but online suppliers provided you are ordering sufficient to get
free on inc carriage can be cheaper..
and less reliable.
What your saying that a hard disk in a sealed pack is less reliable?.
Depends on how it has been handled. I have used suppliers in the past
that supplied new disks in a jiffy bag! (as opposed to the proper shock
protecting padded drive boxes)
Aren't they supposed to be OK with the some i00 odd G or similar?...
Quite possibly... and it sounds like plenty, however its alarming how
easy it is to exceed that. Quick example: lets say you drop a HDD onto
your desk - from a height of 1 cm
If we apply v^2 = u^2 + 2as we get v^2 = 0 + 2 x 10 x 0.01
So it hits the desk at about 0.45 m/sec
Now your desk is hard, but it must give a bit, so lets say if flexes (or
dents) by a tenth of a mm under the impact:
0 = 0.45 + 2a x 0.0001
-0.45 / 0.0001 / 2 = 2250 m/sec^2 or about 225g
OK .. there is an outfit round here who has a hard drive "mincer" it
does just that . His firm collects PC's takes the hard drives out and
puts them in a machine that literally minces them into small chunks!..
We once tried to wreck some hard drives but hitting them with a hammer
and throwing them at the floor not dropping them, throwing them. It was
very surprising just how robust they were even with that treatment.
I suspect that it depends where the heads are WRT the drive surface at
any given time..
Yes, very much so... I have destroyed a few, and it takes a 14lb sledge
to do serious damage to them.
As with lots of these issues, the effect of impact damage is not
necessarily immediate failure, but can manifest as a reduction in life.
Much the same as with static damage.
The main problems we've had with PC's are...
Motherboards .. almost all caused by the duff capacitors that were made
a while ago.
Mostly I would say the same here, although I have had a recent slew of
failures on relatively recent kit with bad caps again.
Power units .. mainly because of their uber low price something has to
be underrated hence the failures, but this applies to a lot of other
consumer grade stuff..
I had that conversation with one of our customers a while back. He
wanted a quote for four new machines, and then queried the price saying
he could buy the same spec off the internet for less. So I explained to
him that the systems I was promoting were not really the same spec but
were built to order units, with business class PSUs, decent mobos etc
and came preloaded with a much closer match to his final software stack
since we could spec what went on them. He was not convinced about the
PSU argument since he believed they had suffered very few PSU failures
in the past. Alas completely missing the irony that he was making my
point for me, since we supplied the bulk of their PCs with decent PSUs!
In the end I ordered him "off the shelf" systems from our normal system
builder at a price closer to his "cheaper" ones. I pointed out to him
later that it took about an extra hour and a half of our time per
machine to configure them for use, and that more than wiped out the
savings.
Hard drives but these seem to be better in recent years..
Yup, don't think I have had many failures recently.
CD ROM drives .. but in more recent times seem to be better.
Memory and processors hardly any..
Memory, now and then. Processors, I can only recall one failure in over
20 years! (that was actually recently on a i3 box, still under warranty)
--
Cheers,
John.
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