Case fan needed (120 MM)

Praetor said:
Well if you've got 10 fan jacks on the mobo than yes. If the fan is too much for the mobo jack then .... the fan simply wont power or it will run underpowered..

thank you at least someone knows what he's talking about......they wouldnt make it if there was a chance that the fan could harm the motherboard :P
 
Praetor said:
Well if you've got 10 fan jacks on the mobo than yes. If the fan is too much for the mobo jack then .... the fan simply wont power or it will run underpowered..

My answer to this is -=BS=-
More fans = more current. Think - what is the purpose of fuses?
They get fried not to let your electicial installation fry. If you run 20A through tiny cable, you will burn it.
If you examine fan rails on PCB of your mobo - you'll notice that they have very small profile surface and that means that they can't stand much current. There are also some regulators and they have limited capabilities too.

its just common sense and basic knowledge of electricity and electronics. Wanna prove?
P = U * I
R = U / I
so
P = U*U / R

around 5 ohms and less should do the job

try putting a small resistor between +12 and GND on your mobo, or even short it. possible things that may happen:
a) mobo fried
b) fan rails fried
c) PSU shutdown (the most possible)

:P :P
 
My answer to this is -=BS=-
More fans = more current. Think - what is the purpose of fuses?
They get fried not to let your electicial installation fry. If you run 20A through tiny cable, you will burn it.
If you examine fan rails on PCB of your mobo - you'll notice that they have very small profile surface and that means that they can't stand much current. There are also some regulators and they have limited capabilities too.
1. No need to get childish and hostile. That'll get you promoted real fast
2. How many fans pull 20amps? Most are in the ballpark of 0.5amps.
3. If you connect a superpowerful fan to a dinky motherboard connector, guess what, it doesnt power the fan (and if it does, the fan is gonna be spining at a whopping 0.5rpm)
4. Yes more fans = more current = more power blah blah ... and how many mobos feature anywhere near 10 fan headers? Fan headers are designed by engineers for a reason -- to connect fans -- and if they didnt think it's safe to connect fans to them then they wouldnt be found on the mobo.
 
Ived been reading this thread, im a newbie here and trying to get some info on building PC, so its ok to put multiple connections(120mm fan) on your mobo without harming it. Seems joelkyr is very persistent on what he knows and would stand firm on what he believes to the point of argueing with a moderator,is that allowed in here.
 
Seems joelkyr is very persistent on what he knows and would stand firm on what he believes to the point of argueing with a moderator,is that allowed in here.
He's certainly welcome to argue his position as long as it stays clean and civilized :) As for his position, Im sure he has a specific example (or should i say counterexample) in mind but Im pretty sure that such cases are anomalous simply due to statistical variance fo 90% of 120mm fans on the market :)
 
does he have a point or what, coz in my belief, you can connect fans on your MOBO, but ived never tried 120mm though.
 
Praetor said:
Fan headers are designed by engineers for a reason -- to connect fans -- and if they didnt think it's safe to connect fans to them then they wouldnt be found on the mobo.

.....of course they are, but mobo manufacturers give info about max load on these headers - often 2 values - max for one connector and max added. That's also for some reason. One thing I have to agree is that power sources decrease voltage, when they're overloaded. But that's not normal behaviour - they are -=overloaded=-. It's a pretty short way from overloading to burning. :)
 
have you been reading the post dude? where were you when we were debating on this matter? :rolleyes: :P it doesnt mean if you are a moderator you can never be wrong and you can never argue with him, right? and i dont think you ever did, am i right? why?:rolleyes: even with a 311 post that you have doesnt impress me, not at all. if you can read my last post i think you certainlly understand my point, im just stating my point which i believed and base on what i know. :cool:
 
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dude i wasnt boasting about me having more than you....if you look at my icon, or my name you can clearly see that 311 is my fav band....and now, my friend you have made me go to 312....lol :P
 
Damn dude, you sound like some old Electronics teacher that thinks he knows everything about computers because he knows what the words wattage and resistance mean.

Do something for me. Go get a computer, then connect enough PCI cards to the mobo to go above your power supplies limit. What happens? The computer most likely won't turn on, and if it does, some of those devices aren't going to be powered. That's how computers are built nowadays.

Maybe back in the days pre-dating DOS you had to worry about frying your board from tryingt o use too much power, more than your machine was built for, but the only time I've ever seen anything remotely like this happen with a modern pc is when some cheapass tries to save an extra 5$ by buying PC Elite or some other ****ing offbrand ghetto 3rd world shit.

I can't count the times I had too many optical drives / hdd's for my comp to power, and all it did was not turn on, or times I had over 6 fans connected with out a problem. I'd really be interested to see what 'quality hardware' you use to fry a motherboard with a fan. Unless that fan was designed to cool your entire house or was some half-assed mexican no name shit, it's very, very unlikely.


In the past 5 years I've built over 30 computers for people, and even more for myself and my family. I've never once had anything like this occur, and if I fried my motherboard by using the available 3 pin fan connectors, using name brand products, I'd send the mobo back for a replacement. If you're that paranoid you could just use a 12v line directly from your PSU anyways.

What next, crashing your harddrive from connection too many usb devices up to your mobo? :rolleyes:
 
I can't count the times I had too many optical drives / hdd's for my comp to power, and all it did was not turn on, or times I had over 6 fans connected with out a problem. I'd really be interested to see what 'quality hardware' you use to fry a motherboard with a fan. Unless that fan was designed to cool your entire house or was some half-assed mexican no name shit, it's very, very unlikely.
First, there's no need to get belligerant. Let's try to keep the arguments civilized (sorry for doing your job Praetor :)).

joelkyr, you're right that if you put too much current through a wire it will fry due to the resistivity of the wire, especially small diamter wires. However, for a 120 mm fan to require that much power it would have to be going pretty fast. How much more current will a 120 mm fan draw than an 80 mm? Let's go to the fan law - power is proportional to the speed cubed times the diameter to the fifth power time the air density. If the 120 mm fan were running at the same speed it would take about 7.5 times as much power. However, 120 mm fans don't need to run that fast because they have a higher flow rate at lower speeds, so if the 120 mm was running at 3/4 the 80 mm speed, it would require about 3 times as much power. Is this enough to fry the motherboard? Probably not. I'd like to think the motherboard manufacturers have some sort of engineering sense. So basically if you're that paranoid about frying the mobo, connect the fans to the PSU, it probably won't matter.
 
Raum said:
Damn dude, you sound like some old Electronics teacher that thinks he knows everything about computers because he knows what the words wattage and resistance mean.

:eek: whoa!! way overboard dude!! this is a forum dude!!! :) I rest my case on this matter, although its informative in some way, but its not going to end i think, no one wants to give in to others opinion, but i think its good and healthy argument, and i dont wanna coz to much bickering in here, my apology to everybody :) and thanks to everybody who contributed with sense on this thread :P
 
Raum said:
Damn dude, you sound like some old Electronics teacher that thinks he knows everything about computers because he knows what the words wattage and resistance mean.

Im a newbie here and as ived said b4, i am watching this thread and it interest me so much coz of the information im getting. I guess everybody here are entitled to their own opinions and views. :) coz we approach problem the way we know it, we just need to avoid harsh word and like YETI said, be civilized.:):)
 
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