Hello!

Kevint_SETI.USA, I hope it's O.K. if I use for an example your pic?!



I took it from here:

SETI Number Crunching Achievements (Graphics OK)

My question is, it's possible to let run "the motherboard" without a box?
Like on the pic, only on wood or metal?

There are no disturbing things like, mobile phone radio beams, broadcast transmitter, and so on...? (I think the translations are bad ;-)
...in order to impair/affect "the PC"?
I thought the box around the motherboard "protect" the cruncher from the waves, radiate and so on? (I think the translations are bad here too ;-)


Greetings!



EDIT:
@ Kevint_SETI.USA
It's only a question, because I wanted to do it too...
...that you understand me correct! ;-)

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My question is, it's possible to let run "the motherboard" without a box?
Like on the pic, only on wood or metal?

Generally that is a bad idea.

There are a lot of high frequency signals flying around the board that will cause radio interference problems to yourself and your neighbours.

As you mention, your system will be suceptible to interference itself. Very unlikely from a mobile phone mast transmitter. However, don't forget that your mobile phone itself is a powerful transmitter... Also your cordless phone...

Just as important, is that the copmputer case should act as a wind tunnel to ensure good directed airflow to keep all components cooled, including the motherboard components.

You also get a physical barrier to stop your cat from frying its paws!

Happy crunchin',
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

It's possible, yes, I'd stay far far away from metal though. wood absorbs moisture, but as long as it's dry and oil free??? Glass works good, but drilling mounting holes in glass can be problematic.


see below/above posts for more, but it will work "outside the box".

beware of flying metal chips and paper clips, though, they can ruin your whole day.

It's possible, yes, ...

Are you running electrical spaghetti spread across a table by any chance?...

Happy crunchin',
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

It's possible, yes, I'd stay far far away from metal though. ...

Metal, I thought because of grounding...



BTW.
So it's not good too, to let run the box with "the opened left side"?
But the "hardcore overclockers" say something different, or? ;-)

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So it's not good too, to let run the box with "the opened left side"?
But the "hardcore overclockers" say something different, or? ;-)

There's a lot of "folklore" and much confusion for all of this... Some of the more wild (and ignorant) Marketing claims also adds to the mis-information...

One article to try is: "The Folk Laws of Case Cooling". Note the incorrect first diagram!

An example case flow is:




Happy crunchin',
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Grounding is a two way street, it can fry or save a motherboard. I have one host mounted on a piece of plywood and hung on the wall for decoration. It is in my bedroom so flying bits of metal should be minimal. I would generally recomend using cases though. Protection from interference and flying debris normally outweights the advanatages of a surface mounted computer.

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BOINC WIKI

BOINCing since 2002/12/8

It's possible, yes, I'd stay far far away from metal though. ...

Metal, I thought because of grounding...



BTW.
So it's not good too, to let run the box with "the opened left side"?
But the "hardcore overclockers" say something different, or? ;-)

I have 7 fans in my overclocked case and it runs 3C cooler with the side panel off. All wires are tucked behind motherboard mount and I have no flat cables at all. Other words my airflow is not impeded but with all the hard drives and burners and such it is cooler without the cover. I also have a machine running in the cardboard box the motherboard came in. When I ran water cooler and peltiers my box was closed with no fans.

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Official Abuser of Boinc Buttons...
And no good credit hound!

Hello!

Kevint_SETI.USA, I hope it's O.K. if I use for an example your pic?!



I took it from here:

SETI Number Crunching Achievements (Graphics OK)

My question is, it's possible to let run "the motherboard" without a box?
Like on the pic, only on wood or metal?

There are no disturbing things like, mobile phone radio beams, broadcast transmitter, and so on...? (I think the translations are bad ;-)
...in order to impair/affect "the PC"?
I thought the box around the motherboard "protect" the cruncher from the waves, radiate and so on? (I think the translations are bad here too ;-)


Greetings!



EDIT:
@ Kevint_SETI.USA
It's only a question, because I wanted to do it too...
...that you understand me correct! ;-)

No problem - If you need some specs and the hows and whys I would help .
The systems shown are all XQ6700's.
The mount shown is now 4 system deep - the final computer on the board is a duo quad 5130 - 8 cores. So the board with a single power cord, network (now wireless) keyboard/monitor and mouse hangs on a wall wall. A single power cord is all that physically connects the unit to the world. Everything else is wireless. Including keyboard and mouse.

One thing I would recommend is use a mount strong enough - not flexible - so the mounted mobo's do not move. And do not mount the mobo's directly to the mounting board. I used 1/4 inch risers.

The entire set is now enclosed in plexiglas - even if I enjoyed watching the cat fray her tail and paws.

I have no problems with this so called electronic noise or emissions - BUNK!

The systems run cool enough without a case-

I have mounted several fans on the "case" several blowing in, and several blowing out.

The entire unit is stable - none of the machines have crashed or overheated. - and are crunching happily 24/7

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I have no problems with this so called electronic noise or emissions - BUNK!

Just because you cannot "see" it doesn't mean that it isn't there.

It's yet another type of pollution, and it's a case of whether it causes enough interference and annoyance for someone nearby for them to chase it up.

You could also try operating your microwave oven without the door on and "see" how much "bunk" that is! (NOTE: DO NOT DO THIS! MUCH HIGHER POWER THAT WILL FRY YOU!)


Happy crunchin',
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

I have no problems with this so called electronic noise or emissions - BUNK!

Just because you cannot "see" it doesn't mean that it isn't there.

It's yet another type of pollution, and it's a case of whether it causes enough interference and annoyance for someone nearby for them to chase it up.

You could also try operating your microwave oven without the door on and "see" how much "bunk" that is! (NOTE: DO NOT DO THIS! MUCH HIGHER POWER THAT WILL FRY YOU!)


Happy crunchin',
Martin

WOW, You really believe a computer case protects like a microwave oven door? The little bit of metal in a case stops nothing. I can close my cell phone in the case and let it ring away,,,does nothing to my screen. The case is merely a mounting frame, nothing more, and some manufacturers even make them out of Plastic.

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Official Abuser of Boinc Buttons...
And no good credit hound!

the amount of rf given off by an uncased pc is SIGNIFICANT it will be enough to interfere with fm receivers etc in the vicinity... there is no question about that

manufactures go to great lengths to shield their equipment so that it passes interference tests.

few manufacturers of pcs use plastic for cases with out also having a separate faraday cage or a spray on metallic shielding compound

regards

adream

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63. (1) (b) "music" includes sounds wholly or predominantly characterised by the emission of a succession of repetitive beats

Yep. Nickel shielding spray is magic stuff when trying to get interference out .....

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"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

I have no problems with this so called electronic noise or emissions - BUNK!

Fortunately, Kevin, you aren't my neighbor.

The odds of RFI getting in to the computer are pretty low, and the motherboard itself has a ground layer running through the middle of the board largely to reduce RFI -- same for all of the other circuit boards.

Good cabling reduces the chance of RFI as well as lowering the possible error rate.

... but all of that said, it isn't RFI getting into the computer, it is RFI getting out.

You can't test this just with a cell-phone (most are digital, and fairly immune to noise, so it's a bad test) or even a broadcast FM receiver.

You can bet that if you are near an airport, and your computer puts out spurs around 120 MHz, someone will come knocking on your door. Same with public service frequencies. If you interfere with the local taxi company and their dispatch radios, you'll likely get away with it for a long time.

As an aside, the case does provide some shielding, but the biggest RFI problem is cables. Even if the box was nicely shielded, a poor cable can make a great antenna.

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Not to mention if you have a decent home stereo, or home recording setup, then amplifier output stages can ( especially MOSFETs ) can spontantiously go into high frequency oscillation ( inaudible ), and rob power at best, or go boom (audible). [the speaker cables act as antennae]

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"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

Not to mention if you have a decent home stereo, or home recording setup, then amplifier output stages can ( especially MOSFETs ) can spontantiously go into high frequency oscillation ( inaudible ), and rob power at best, or go boom (audible). [the speaker cables act as antennae]

Not so likely with a decent home stereo.

If you have a really good home stereo, it is much more likely.

The filters that would block RFI on the cables also add distortion, and on top-end equipment, the designers may very well design those filters to minimize distortion, at the expense of increased susceptibility to RFI.

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Not to mention if you have a decent home stereo, or home recording setup, then amplifier output stages can ( especially MOSFETs ) can spontantiously go into high frequency oscillation ( inaudible ), and rob power at best, or go boom (audible). [the speaker cables act as antennae]

Not so likely with a decent home stereo.

If you have a really good home stereo, it is much more likely.

The filters that would block RFI on the cables also add distortion, and on top-end equipment, the designers may very well design those filters to minimize distortion, at the expense of increased susceptibility to RFI.

True partly, especially within the design bandwidth of the amp but I'll add...

(Warning technical stuff)
in this case i am referring to the negative feedback from the output of the amp (speaker cables), not the input (which is filtered). Even low, mid and high end amps do have capacitors to syphon this off to ground. This sets the bandwidth of the amp & other parameters. but at very high frequencies there are impedance rises in all circuits rendering them 'wierd'. RFI tends to 'pool' where you don't want it,

Now add that amplifiers are used in just about everything electronic. including life support & communications gear then that's why there's regulations for this stuff.

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"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

A couple years ago I saw on a website that someone had set up a trayful of motherboards, maybe 24, without individual cases. I don't think he had them encased at all. Somehow he had them all connected to one keyboard and monitor. That probably was a fire hazard.

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A couple years ago I saw on a website that someone had set up a trayful of motherboards, maybe 24, without individual cases. I don't think he had them encased at all. Somehow he had them all connected to one keyboard and monitor. That probably was a fire hazard.

Thing is it would probably work just fine...LOL

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"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

i had six systems in a cage/storage thing sold by Target..
would hang the motherboards using nylon ties and the hard drives
and power supply would sit on the bottom.
Four duron 1.8 ghz, a p3 1.2 ghz and a celeron 900mhz.
what i called "the cage" over an ac duct.
never had any problems
just kept a can of compressed air to dust off occasionally.

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