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How do i hook up and power all these fans?????

Last response: in Components
December 21, 2006 6:34:28 PM

sometime soon i wanna get a new build, get a nice cheap case (found one for £10 with space for one rear, 3 side (with a little drilling, and one big front fan) and puts lots and lots of fans on it. but no motherboard will come with a whole side edge dedicated to fan connectors, so how should i link all these fans to my PSU? (bearing in mind i havent got my new PSU yet - perhaps modular ones come with lots?:/...unlikely)

also, on a different note, the reason for these fans is for air flow through a big e6300/e6400 what do you think if i took the side off the case, glued a few fans together and replaced the case side with the wall-of-fans? lol...too noisy? ineffective? may aswell just leave the side off? i really have no idea. i havent had the side on my case for ages and the GPU fan is the only noise coming from it...its annoying bbut CPU fan is would other case fans be as silent?


More about : hook power fans

December 21, 2006 6:55:00 PM

chain them together? you mean one goes into another which goes into another which plugs into a molex?
December 21, 2006 8:04:11 PM

oh! i didnt know that, thanks:) 

thats why i love forums
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December 21, 2006 8:26:29 PM

When I build a computer with a lot of fans and lights I place a Micro-ATX power supply (150-350W) in the bottom of the case or below the CD-DVD drives if there is room. I run all of the case fans and lights from it and just use the system PSU to run the computer components and CPU fan. All you have to do is cut the green wire and any black wire from the motherboard plug and wire them to a switch to start the small power supply. If you wire the green and black together the PSU will power up as soon as you plug it in (or turn on a power strip it is plugged into). I use a Dremmel to cut a small hole in the back of the case for the Micro-ATX power cord to go thru. Then drill a hole somewhere for the switch and you are done. I have been doing this for years and have done many systems with no problems yet. The Micro-ATX power supplies are much smaller and will fit in most midtower cases or larger.
December 21, 2006 8:32:34 PM

that is an excellent idea! cheap 300/350W PSUs only cost 5/6 pounds. but are fans and lights really that much of a drain on a PSU? i dont know how much fans take up...i suppose lights would use a alot...
December 21, 2006 8:46:51 PM

my suggestion would be getting a fan controller that fits either 3.5" or 5.25" front bay, alot easier w/o the hassle of modding and re-wiring

December 21, 2006 9:01:59 PM

i was about to say "most fan controllers only do 3 fans"..but i suppose if you linked 2 fans together then you could control the back fans with one switch..the side fans with another swith and front/top fans with the third? (will that work? lol)
December 21, 2006 9:09:28 PM

Best advice - buy an EXPENSIVE case which does NOT require 27 fans in it.

Believe me, a box full of fans will fuck you off something fierce. Guaranteed.
December 21, 2006 9:10:02 PM

Fans use about .08A and lights don't really pull more then 1A.

I think he meant 0.8A for the fans

my thermaltake fans' spec on the box:

0.15-0.48A for 80mm fan and 90mm fan
0.12-0.48A for 120mm fan

my 12" pulls 500mA, which is 0.5A

December 21, 2006 9:15:45 PM

As in almost any endeavor there is the law of diminishing returns. At some point more fans will not help cool the parts under heat sinks. Here is some background, using plumbing as an analogy. Consider heat generators as pumps. Consider the interface between the pump and a heat sink as a certain size pipe. Considering it this way, if the pump increases speed (puts out more heat), the flow through the pipe increases up to a point where no more water (heat) can flow through that size of pipe (quality of heat sink interface). This is why there are after-market heat sink compounds overclockers use because they decrease the interface heat resistance (in plumbing terms, increase the size of the pipe).

The heat sink itself can be thought of as a plumbing pipe of a particular size. At some point it reaches saturation and cannot transfer any more heat out of it than heat is put into it. Blowing a fan on a heat sink helps, keeping the plumbing analogy going, as drain pipe connected to the heat sink. This is why when you blow harder on the heat sink, you can get more heat out of it. That said, at some point, more blowing will not get any more heat out because the heat sink itself has a limit to the speed it can transfer heat from the interface to the heat generator and it's fins.

Practically, a front case fan, a rear case fan, a side fan and top fan will be the maximum number of fans you can use before the laws of diminishing returns kicks in. In other words, one more fan will not help remove the heat from a heat sink that is already at it's limit in how fast it can transfer heat.

Adding a little more analogy that helps clarify things, consider a solid bar of copper. If you hold one end of it and apply a torch to the other end, you will notice that the end you hold does not get hot for some period of time. This because any metal has a thermal resistance. Complicating things is the fact that as the heat is applied to the one end of the bar, heat is not only traveling through the bar to the other end, but it is radiating into the air surrounding the bar. This gets me to the principle of fins. If you have fins attached to the bar, much of the heat will be radiated into the air through the fins and you would find it takes a lot longer for the end of the bar you are holding to get warm.

It is important to understand the limitations of a heat sink because microprocessors and graphics processors generate a lot of heat and as they work harder, the rate of heat they generate goes up. Not only is their a limit in how fast you can transfer heat through the interface (the heat sink compound on top of the chip between it and the heat sink), there is also a limit in how fast the heat can be removed from the heat sink. At some point the chip gets too hot and fails.

Now, some overclockers are using water blocks since water (keeping the plumbing analogy) is a bigger pipe (lower thermal resistance) than metal. In addition, since the water is being circulated, new cool water is constantly coming into the water block on top of the chip. There is still that pesky interface between the water block bottom face and the top of the chip itself. At some point, no matter how fast the water flows, the chip will overheat, assuming the chip is being overclocked.

I hope this information helps you understand why, at some point, adding more fans won't benefit you.
December 21, 2006 9:19:04 PM

lol, i dont know if an expensive fan will push more air than 27, lol. but you would surely need at least one at the back, one at the front and one at the side if you dont want to spend much on a CPU cooler...which is pretty much why i'm asking.

i would like to use stock cooling and buy a few £1 fans to help cooling if i OC it.

i read the E6300 3Ghz on stock cooling budget guide...and if i can get somewhere near that without forking out £50 for a giant HSF with pipes and fins covering the motherboard.

i really have no idea, though...but budget is definately an issue...what do you all think?
December 21, 2006 9:19:13 PM

yep, I'm an airflow freak myself, but make sure the fan controller's specs has a decent watts-per-channel, AND a decent PSU would help alot

mine has 18W max per channel, which theoretically means I can hook up as many fans in one channel as I want w/o exceeding the 18W limit. But for your safety, I wouldn't recommend pushing the channels that harsh, maybe 3 fans max on each channel. (9 fans?!!? really not worth it, especially in a midtower case)

I used to think exactly like you, until I found another solution, a 120mm fan in the 5.25" front bay, but it take up 3 slots though.

or this one if you don't have a black case

hope this help :D 
December 21, 2006 9:25:57 PM

oof! 3 slots:| i couldn't do without 3 slots..well, ATM 3 is all i have:p  when i upgrade i'm not getting anything less than 4...but i have a DVD drive and X-fi front panel..and will get another DVD drive (they're so cheap it's worth it for the convenience)

but a big fan on the front does lead to another point...those fans situated at the bottom of alot of cases...presuming you dont have 9 HDDs a decent amount of air will get through, but all CPUs are at the top of the case, right? so do they actually do much?
December 21, 2006 9:28:55 PM

hmm, yeah..a top-mounted fan would be good...but i dont think i'll be able toa ffdord a case with one/a hole for one...unless i drill/cut a hole.

but looking at my HSF...there's space on two sides (the top and the right as you look at it) that you could place fans on....would that do just as well as a fan in the top of the case or would something strange happen there? would you need one blowing away and two blowing in or what?
December 21, 2006 9:43:29 PM

yeah, that is the best idea...i'll probably get a DS4 mo/bo with those heat sinks all over it so air flow past them would help them out

10C drop is pretty good.

thanks, you've been really helpful:) 

but one last uestion...i had a quick look at fans...some say the have 4pin connectors..and a couple are pictured with molex cables(IDE drive power cables) they take diffewrent power or are the molexs a molex-to-fan converter or soemthing?

becasue you mentioned molex...but if fans i get dont have molex (or adaptors) i'd have to chain them through the single motherboard connector? and i dont think that would be a good idea through a P4V88 mo/bo...would the voltage fuck it over do you think?

i really have no idea about these things:/ sorry, lol.
December 21, 2006 11:51:30 PM

a fan adapter could solve some issues

it'll convert a 3-pin connector to a 4-pin molex connector, plus, you can connect a 3-pin fan and a molex-fan together and power them with the molex connector