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Date:      Sun, 2 Sep 2001 23:44:45 -0700
From:      "Ted Mittelstaedt" <tedm@toybox.placo.com>
To:        "Mike Porter" <mupi@mknet.org>, "Sean Chittenden" <sean@chittenden.org>, "Bsd Newbie" <bsdneophyte@yahoo.com>
Cc:        <freebsd-questions@FreeBSD.ORG>
Subject:   RE: overclocking and FreeBSD stablity...
Message-ID:  <002a01c13443$eae64fe0$1401a8c0@tedm.placo.com>
In-Reply-To: <200109022037.f82KbZl09087@c1828785-a.saltlk1.ut.home.com>

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>-----Original Message-----
>From: owner-freebsd-questions@FreeBSD.ORG
>[mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Mike Porter
>
><snip possible urban legend story>
>
>> I've heard this story before, usually from people wanting to overclock, and
>> I really question that this actually happens.
>>
>I actually got it from Tom's Hardware guide.  It has been there for a *long*
>time, and I would imagine that Intel has had ample opportunity to
>get them to
>take it down *if it wasn't true* ("umm...if you don't take it down, we won't
>ship you any more pre-release chips" ).  This story has been circulating a
>long time, and Intel has surely had many many opportunities to deny it.

I think that Intel knows that it's in it's interest to allow as much
speculation to circulate on how their processes operate as possible. :-)  If
they got Tom's to take it down then it would be proof that this is how they
really do it - better to leave it up so people keep guessing.

  The
>cynical side of me is inclined to argue that they might not *want* to deny
>it, as it leads to more people overclocking, thus more people frying chips,
>thus intel sells more chips.  However, Intel has almost certainly lost
>revenue from overclocking; look at the pains they took with the PentiumII to
>try to "lock" the chipset clock and multiplier to settings inside the chip.
>(and the p3, too....I don't know about the p4 but I suspect the same to be
>true there).  AMD also, with the athlon's, although that is fairly easy to
>defeat on the Thunderbird/Duron chips.
>

Actually I don't think that they've lost that much revenue as long as the
OEM's don't start regularly overclocking.  Right now Gateway and Dell don't
sell "overclocked" systems. ;-)

>>
>Why would you build a run of a product that is capable
>of 800Mhz ( I think that is what the current Celerons can run to), then
>retool everything to build a 750Mhz part that is *identical in all respects
>except rated clock speed* to the 800Mhz part?

I don't know but one speculation that I have is based on the known fact of how
chip plants age.

For example, suppose you have a 400Mhz design that allows a max of + or - 5
microns variation of the traces.  You also have a 800Mhz design that requires
maximum + or - 2.5 microns variation.

You tool up a plant to meet the maximum 2.5 micron variation.  In the first
quarter of it's lifespan, the equipment is still being adjusted and so you
cannot maintain the 2.5 consistently, but you can stay under 5.  So, you run
400Mhz parts on it.  Then, the next 2 quarters of the plants lifespan you've
gotten the equipment broken in and you can maintain the 2.5 consistently, so
you run 800Mhz parts on it.  Then, the last quarter the equipment is starting
to get worn out and cannot maintain the 2.5 consistently anymore so you go
back to 400Mhz parts on it.

>
>Do they actually do this?  I can't say, since I don't work for Intel.  I
>suspect that those that do can't say either, unless Intel decides to
>officially comment one way or the other.  I am pretty sure that they
>don't do
>this with the top-of-the-line chips, as they want to get the maximum number
>of higher-clocked chips out there, to support the R&D cost.  It is also
>likely that AMD at leased *used* to not test the way, for much the same
>reason (as an uderdog, they want to get the maximum number of
>highest-performing chips out there).
>
>
>test, and one of the overclocked mobos actually performed more poorly than
>its more conventional counterparts.  go figure...overclocking doesn't ALWAYS
>work!)  (and even then, some of the problems people have with certain
>motherboards may be do to exactly that...swapping out a CPU might fix the
>problem...)
>

I've actually seen this myself on a set of old 386's - both were acting up,
and swapping the CPU between them fixed both.  Could have been corrosion on
the
contacts but who knows?

>>
>Again, there is no real difference between a chip running at 600 Mhz and a
>chip running at 500Mhz, so why go to the effort of setting up the line to
>produce 600Mhz parts?  Isn't it easier to simply test the parts as they come
>out of production, and label them according to what they can do?  And isn't
>it more effective?  If you can sell a part rated to 700Mhz, wouldn't
>you want
>to capture that revenue?  Granted tends to argue for testing each chip
>individually, but there are economies of scale involved, and ease of access
>to the parts to test....
>

The only problem with this that I can see is that the tests only attempt to
simulate real world, they aren't real world.

Testing gets you 99.9% of the way there, but that last .1% can screw you.
Intel found that out with the busted FPU on the early Pentiums debacle.  I'm
sure that their test set ran the FPU up, down, sideways and 6 ways to Sunday
but it wasn't good enough.

>> >The other wrinkle in this scheme is that Intel is completely free, if the
>> >demand is there, to remark their OWN chips to a LOWER speed.  So if demand
>> >spikes for a 300Mhz Celeron, and they have a pile of 450Mhz Celerons
>> > sitting on the shelf, there is nothing illegal, immoral, or fattening
>> > about calling them 300Mhz Celerons and pricing them accordingly. (after
>> > all, they passed as
>> >450Mhz celerons..and don't forget, any given chip in the lot of 450's has
>> > a one-in-ten or so chance of being capable of much faster speeds than
>> > even 450Mhz).
>>
>> Once more I've been told this is a crock, because Intel cannot afford to
>> have a
>> "pile" of CPU's sitting around, the economics of chip prices are such that
>> every day that a completed CPU sits there and isn't bought, the company
>> loses money on it.
>>
>Exactly my point.  If they begin to accumulate a "pile", they have a very
>strong incentive to mark them down until they sell.  If they accidentally
>build too many 800Mhz celerons, are they going to wait until they sell, or
>are they going to sell them as 700Mhz celerons?

They usually seem to fix this kind of problem by adjusting the prices.
Remember when Intel decided to stop producing non-MMX Pentium 200's?  Well
there are tons of systems out there which have motherboards that will happily
clock up to 200Mhz but were shipped with Pentium 133's - but don't have the
different voltage that the 200MMX parts demand.  Yet, when that started
spiking the demand for 200Mhz non-MMX chips, Intel simply dropped the price on
the newer generation chips and _still_ stopped selling the 200Mhz non-MMX
chips.

>
>There is a great deal of interest in this, just not from Intel or
>AMD.  Intel
>and AMD make money by selling people faster chips, not by selling them ways
>to make existing (slower) chips faster.  There are a couple of interesting
>active cooling designs that are quite efficient.  The most interesting rely
>on thermoelectric properties of some metal compounds (apply an electric
>current to one piece of metal, and the other becomes colder, often
>significantly so (this is the inverse of the effect that witht he same to
>metals, if one is hotter than other, will generate electricity.  And that's
>as far as my knoweldge of that extends).  The least promising includes
>hooking up a garden hose to your CPU tower.  The idea of all that water
>inside my case doesn't make me very happy, though it supposedly works quite
>well.
>

Aren't they using Ethlyne Glycol automotive anti-freeze in those cases instead
of plain water?

I agree that a water-based cooling system is not a good one for a desktop
system.  Water expands when it gets hot and that has to be designed in.  Cars
do it by venting to atmospheric through a pressure valve which creates a leak
point.  They can get away with it because if a problem develops you just
dumping coolant onto the ground.  Imagine that in a home! ;-)


Ted Mittelstaedt                                       tedm@toybox.placo.com
Author of:                           The FreeBSD Corporate Networker's Guide
Book website:                          http://www.freebsd-corp-net-guide.com



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