Hardisk cooling problem...

[AZL]

yeah... i agree that it caused by EMF. i think that is not a good idea putting HDD (+floppy) near with any EMF source or any radio wave. the HDD is part of magnetic too...

[Noia]

Er, the internal systems of computers run on DC, and DC power does NOT generate a harmful EM field to electronics because there is no induction.

I mean, you have fan's on your CPU's right?

Oh, also, the HDD is Shielded, theres a Wooping Magnet on the inside tho, used the shift the head but using a Coil of wire which a current is passed through, when inside a magnetic field, you get the Motor effect.

[Und3ertak3r]

Noia.. i agree with most of your comments.. except..

the internal systems of computers run on DC, and DC power does NOT generate a harmful EM field to electronics because there is no induction

well yes and no.. yes.. there are no AC EM fields as in from AC Mains electricity.. but you do have EM fiels generated by the data flowing in the cables.. also as the current varies to hi drain components ie HDD motors, cd rom motors.. AC em fields are generated ALSO.. The DC EM Fields Have to be taken into account.. read basic electro magnetic theory..

That is the disagreement.. These fields are usualy self cancelling, or nulled due to the distances involved .. the shielding of the hdd is sufficient for most and stronger fields that are encountered in a computer..

I certainly wouldn't be running the power lead to the hdd or any cooling fans parrallel with the IDE cable (ie strapped to the cable and running more than 5cm parrallel)..
The the CPU is not a magnetic device, your HDD is.. Note: I had a prob with a system a while ago slow as.. blame fell on the HDD.. when the HDD was tested in another system all ok.. tested electricly in the customers system all ok.. remounted. sloooow as.. PC speaker mounted just above hdd.. magnet almost against the case.... moved all ok..
But I suppose I argue over a few milligause (in other words I nit pick)

On to other matters.. Heat sinks on the underside of the heat source? dunno.. heat rises.. a spreader on the underside..ie to transfer the heat away from a hot spot..but only manages to heat other areas .. most of the heat in a HDD is mechanical heat.. so heatsinks and a reasonable air flow over the top (convective is ok in some climates) will keep the HDD at an acceptable temp.. oh remember the Metal brackets that the HDD is attached to.. the better the bond here the better the heat transfer to the case (verygood heatsink esp if it is aluminium) so a couple of HS fins on the top of a hdd and a good airflow.. the hdd wont get too hot..
oh what is hot?
If you touch the device and the manufacturers logo is ledgeable on your finger..it is toooo hot.. seriously.. if you can touch it comfortably for more than 5 seconds the temp is OK.. If it is 1..2.. ouch.. get the cooling going..
test the hdd after the system has been running 15mins then after 1hr.. (give it a bit of work during this time) use the lo-tech approach I mentioned..
BTW..Do the tests with the Case sides on.. well run the machine with the sides on.. (takeing them off to test the hdd temp)

Cheers

[steve.milner]

Originally posted here by Noia
Er, the internal systems of computers run on DC, and DC power does NOT generate a harmful EM field to electronics because there is no induction.

To make a motor work on DC you need either a brushless or a brush motor look here for a desription.

Either way you will be generating a moving magnetic field as either the aramture windings reverse polarity or the magnets move round.

But, I would very suprised if this is causing the slowdown of the PC. <edit> Wow, undertaker - I'm suprised the speaker casued that, but I live & learn!</edit>

To try and isolate the problem:

Try switching the power saving features of the bios off to see if that eliminates the slow down.

Certainly run the fan from a deperate power supply.

Ensure that the fan is not interfering with the air flow to the CPU by performing the tests with the fan in a differing position. If the CPU begins to overheat the CPU may be slowed down to compensate.

HTH

Steve

[IKnowNot]

I'm going to play devil's advocate here; my first impression reading this thread was that JohnHACK would be dumbfounded by the responses, not because he could not understand the concepts, but because he may not be able to translate them. He is from a non-English speaking country ( AZL correct me if I am wrong ) and from his post is not fluent in English.

Yes, I am guilty of it too, and someone will no doubt refer to this post in the future to embarrass me, but I think the responses made to an individual should consider their level of command of the language in which this forum is in.
( note here, I do believe that eventually, facilitated in large part to the Internet, there will be one language world wide with which to communicate, and since the U.S. does not have a national language, it will be up to the Britts to push for English: guess I better brush up on my German! But that is for another forum to debate. )

As I understand the thread so far, it reads as follows.

Cheyenne1212: power supply may not be big enough with extra fan so “hardisk” is not getting enough power

DeadAddict: puts a number on how big power supply needs to be

White_Eskimo: says wind from fan might slow down drive, and includes a link to system monitor ... excuse him, he is upset because he has to go back to school, but obviously needs it to learn to spell “tomarrow” ( sorry, couldn't resist that )

nihil: fan motor interference causing problem

Und3ertak3r: small extra fan on case usually enough

Cybr1d: use heat sink instead, may work just as good for cooling “hardisk”

Swampy_ finger and fl34bit3: heat rises, whatever you use, put it on top

Noia: says the DC current in your fan can't hurt ( ? )

Und3ertak3r: questions Noia's theories about DC current.

And steve.milner suggests that the fan used may be interfering with the cpu fan.

My reply:
from reading JohnHACK's profile, he has a computer which creates a lot of heat. An extra cooling fan on case can help if there is enough power, a heat sink on top of the “hardisk”might help if the drive is in fact getting hot. There is always the option of buying a “hardisk” cooler if it is really necessary. In this case running cool is best, cold is not. ( Do we have any superconductors here ? )
The problems asked about could be due to lack of power or magnetic fields, or maybe something else, we would need more info to give a more accurate guess.

JohnHACK never said what kind of fan he used or how it was powered, and never said what type of case or hard drive is used or how old, or how fast ( 5400 rpm, 7200 rpm, 10,000 rpm ). A faster drive will generate more heat, a newer drive may dissipate heat better and may not need extra cooling ( most drives I have seen made in the past five years use thin aluminum on the top for better cooling as well as being cheaper ). He never even said what the computer is used for; all else being equal, a gaming machine with 64 megs of RAM will create more heat in the hard drive then a secretary's work station with 512 meg a RAM.

O.K., I'll get off that soapbox and focus on something else here.

Und3ertak3r's comments about “electro magnetic theory”; maybe it has been too many years, but I'll be damned if I can remember anything remotely specific from physics, my hat is off to you! ( but I'm drunk, old, and have music blasting in my ears)

Concerning Noia's comments about DC EM fields, I'll say this: my refrigerator is loaded with magnets from old hard drives, but those magnets were strategicly located in the drives. ( wait a minute Und3ertak3r I remember something, magnetic fields flow in certain patterns don't they? ). I bet you a GUINNESS that I can make a DC magnet, which runs on a common battery, that will make your hard drive information as useless as **** on a bull. What is in a fan motor? And why do they make shielded cable for DC applications ?

just my thoughts.

Reason for Edit: steve.milner's PM.

Edit:
I found the responses to this thread too intense IMHO for someone with English as a second language.

I deal with non-english speaking people ( many, many languages ) on a daily basis, and the outcome of our encounters can be extreme for them. As such I may be more sensitive to the issue, but my intent was to bring this to light, NOT mock anyone. If anyone is insulted, that is not my intent. If I can change this to better portray my intent, let me know.

[jinxy]

I may be way off base here but a fan has a motor that has a magnet in it. I would think that putting a magnet near a hard drive must be a bad thing. If you realy need to call your HDD i would position a fan away from the HDD but so it plows air directly at it.

There are also some good points made by others here. But although i am no expert, i do now that everything has its optimum running temperature. So to my mind cooler do's not always = better performance.

[White_Eskimo]

White_Eskimo: says wind from fan might slow down drive, and includes a link to system monitor ... excuse him, he is upset because he has to go back to school, but obviously needs it to learn to spell “tomarrow” ( sorry, couldn't resist that )

?? err, i thought this was a security site, not grammar/english checking site. Guess I'll go back and re-read AO's rules and guidelines...

[Swampy_ finger]

QUOTE: [" a fan has a motor that
has a magnet in it. I would think
that putting a magnet near a hard
drive must be a bad thing."]

Yes but arent hard disk magnetically shielded from low grade magnets such as fans

[jinxy]

Swampy, to be frank i don't no if hard disk has any magnetic shielding. But i worked for a company that dealt with EMI supressing material and i have never seen anything around a hard drive that would protect it from a magnetic field.